AP Math Revision › AP Precalculus › Unit 1
AP Precalculus Unit 1: Polynomial and Rational Functions
How two quantities change together; average rates of change and what they say about increasing, decreasing and concavity; the patterns of change in linear and quadratic functions; zeros (real and complex), multiplicity and end behavior of polynomials; zeros, vertical asymptotes, holes and end behavior of rational functions; equivalent forms (factoring, long division, the binomial theorem); transformations; and choosing, building and judging a function model.
CED topics in this unit: 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 1.10, 1.11, 1.12, 1.13, 1.14.
Key formulas and facts
- Average rate of change of $f$ over $[a,b]$: $\dfrac{f(b)-f(a)}{b-a}$, the slope of the secant line. Units: output units per input unit.
- Linear functions: equal input steps give equal output differences. Quadratic functions: equal input steps give average rates of change that change by a constant amount (constant second differences).
- Concave up on an interval: the rate of change is increasing there. Concave down: the rate of change is decreasing. A point of inflection is where the rate of change switches between increasing and decreasing.
- A degree-$n$ polynomial has exactly $n$ complex zeros counted with multiplicity, at most $n-1$ turning points, and nonreal zeros in conjugate pairs $a\pm bi$ when its coefficients are real.
- Multiplicity: at a zero of odd multiplicity the graph crosses the $x$-axis; at a zero of even multiplicity it touches and turns back.
- End behavior of a polynomial comes from its leading term $a_nx^n$: for example, $\lim_{x\to\infty}(-2x^4+x)=-\infty$.
- Rational function $r=\frac{p}{q}$ in lowest terms: zeros where $p=0$; vertical asymptotes where $q=0$. A factor that cancels completely from the denominator gives a hole instead.
- Horizontal asymptote: degree of $p$ less than degree of $q$ gives $y=0$; equal degrees give $y=$ (ratio of leading coefficients); degree of $p$ one more than degree of $q$ gives a slant asymptote (the quotient from long division).
- Binomial theorem: $(a+b)^n=\sum_{k=0}^{n}\binom nk a^{n-k}b^k$. Remainder theorem: dividing $p(x)$ by $x-c$ leaves remainder $p(c)$.
- Transformations of $y=f(x)$: $f(x-h)+k$ shifts right $h$ and up $k$; $af(x)$ is a vertical dilation by $|a|$ (a reflection over the $x$-axis if $a<0$); $f(bx)$ is a horizontal dilation by $\frac1{|b|}$ (a reflection over the $y$-axis if $b<0$).
Worked examples
- Average rate of change: for $f(x)=x^2-3x$ on $[2,5]$, $\frac{f(5)-f(2)}{5-2}=\frac{10-(-2)}{3}=4$.
- Second differences: the outputs $1, 4, 11, 22, 37$ at $x=0,1,2,3,4$ have first differences $3, 7, 11, 15$ and second differences all $4$, so a quadratic fits: $y=2x^2+x+1$.
- Complex zeros: $p(x)=x^3-x^2+4x-4=(x-1)(x^2+4)$ has zeros $1$, $2i$ and $-2i$.
- Sign chart: $\frac{(x+1)(x-2)^2}{x-4}<0$ on $(-1,2)\cup(2,4)$; the sign does not change at $x=2$ (even multiplicity) and $x=2$ itself gives $0$, so it is left out.
- Hole and asymptote: $r(x)=\frac{x^2-x-6}{x^2-9}=\frac{(x-3)(x+2)}{(x-3)(x+3)}$ has a hole at $\left(3,\frac56\right)$, a vertical asymptote $x=-3$ and a horizontal asymptote $y=1$.
- Slant asymptote: $\frac{2x^2-x+3}{x+1}=2x-3+\frac{6}{x+1}$, so $y=2x-3$.
- Binomial theorem: the $x^2$ term of $(3x+2)^4$ is $\binom42(3x)^2(2)^2=216x^2$.
- Transformation: if $(4,-2)$ is on $y=f(x)$, then $(2,1)$ is on $y=-\frac12f(2x)$.
Common traps
- Calling every zero of a denominator a vertical asymptote: check whether the factor cancels first (then it is a hole).
- Giving a zero of a rational function where the denominator is also zero: the function is undefined there.
- Reading $f(x+3)$ as a shift right: it moves the graph $3$ units left.
- Deciding end behavior from a large middle coefficient: only the leading term matters as $x\to\pm\infty$.
- Writing an average rate of change without units, or reversing the order of the subtraction in the numerator and denominator.
- Forgetting that a real-coefficient polynomial with zero $3+i$ also has zero $3-i$, which raises the least possible degree.
- Extending a model outside the inputs where it makes sense (negative heights, negative volumes, times after an event ends).
Practice questions
127 multiple-choice and 4 free-response questions, each tagged with its CED topics and with "No calculator" or "Graphing calculator". Try each one before opening the answer. Each line of a free-response scoring guide is one point, and every free-response question here is out of 6. 33 of the 127 multiple-choice questions here need a graphing calculator; on the May 2027 exam, Part A of the multiple choice is 29 questions with no calculator and Part B is 13 questions with a graphing calculator. A free account opens the worked answers and scoring guides of 20 questions a day; Pro opens every one.
Question 1 · Multiple choice
CED 1.1No calculatorThe graph of $y=f(x)$ is shown, where $f(x)=x^3-6x^2+9x$. On which interval is $f$ decreasing?
- $(0,3)$
- $(1,3)$
- $(3,\infty)$
- $(-\infty,1)$
Question 2 · Multiple choice
CED 1.1No calculatorThe table shows the distance $d$, in miles, that a cyclist is from home $t$ hours after leaving. Which statement best describes how $d$ changes as $t$ increases from $0$ to $4$?
| $t$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $d(t)$ | 0 | 3 | 8 | 15 | 24 |
- $d$ increases by the same amount each hour
- $d$ increases, but by a smaller amount each hour
- $d$ decreases each hour
- $d$ increases, and it increases by a larger amount each hour
Question 3 · Multiple choice
CED 1.1No calculatorLet $g(x)=(x+2)(x-1)(x-5)$. For which values of $x$ is $g(x)<0$?
- $(-2,1)\cup(5,\infty)$
- $(-2,5)$
- $(-\infty,-2)\cup(1,5)$
- $(1,5)$
Question 4 · Multiple choice
CED 1.1No calculatorLet $h(x)=8-\frac{x^2}{2}$. Which statement describes $h$ on the interval $[0,4]$?
- $h$ is decreasing, and its rate of change is decreasing
- $h$ is decreasing, and its rate of change is increasing
- $h$ is increasing, and its rate of change is decreasing
- $h$ is increasing, and its rate of change is increasing
Question 5 · Multiple choice
CED 1.1No calculatorThe graph of $y=f(x)$, where $f(x)=-x^2+2x+3$, is shown. On which interval are both $f(x)>0$ and $f$ increasing?
- $(1,3)$
- $(-1,3)$
- $(-\infty,1)$
- $(-1,1)$
Question 6 · Multiple choice
CED 1.1, 1.5No calculatorThe table gives values of a quadratic function $f$. Between which consecutive $x$-values in the table must $f$ have a zero?
| $x$ | -2 | -1 | 0 | 1 | 2 | 3 |
|---|---|---|---|---|---|---|
| $f(x)$ | 7 | 2 | -1 | -2 | -1 | 2 |
- Between $-1$ and $0$, and between $2$ and $3$
- Between $0$ and $1$, and between $1$ and $2$
- Between $-1$ and $0$ only
- Between $2$ and $3$ only
Question 7 · Multiple choice
CED 1.1No calculatorThe height, in feet, of a ball $t$ seconds after it is thrown is $h(t)=-16t^2+48t+4$ for $0\le t\le 3.1$. During which time interval is the ball rising?
- $(1.5,3.1)$
- $(0,3)$
- $(0,1.5)$
- $(0,3.1)$
Question 8 · Multiple choice
CED 1.1Graphing calculatorLet $f(x)=0.2x^3-1.4x^2+2x+4$. The function $f$ is increasing on $(-\infty,a]$ and on $[b,\infty)$, and decreasing on $[a,b]$. To three decimal places, what is $a$?
- $0.880$
- $3.786$
- $2.333$
- $4.812$
Question 9 · Multiple choice
CED 1.1Graphing calculatorLet $g(x)=x^4-3x^3+x+2$. On the interval $1\le x\le3$, the graph of $g$ changes from decreasing to increasing at exactly one value $x=c$. To three decimal places, what is $c$?
- $-4.318$
- $2.198$
- $1.500$
- $3.000$
Question 10 · Multiple choice
CED 1.1Graphing calculatorThe height of a weather balloon, in meters, is modeled by $h(t)=-0.3t^3+2.2t^2+1.5t+5$ for $0\le t\le7$, where $t$ is in minutes. To the nearest thousandth of a minute, at what time is the balloon highest?
- $30.106$
- $2.444$
- $5.209$
- $7.000$
Question 11 · Multiple choice
CED 1.2No calculatorWhat is the average rate of change of $f(x)=x^3-2x$ over the interval $[1,3]$?
- $22$
- $11$
- $13$
- $\frac{25}{3}$
Question 12 · Multiple choice
CED 1.2No calculatorThe table gives the temperature $T$, in degrees Fahrenheit, of an oven $m$ minutes after it is switched on. What is the average rate of change of $T$ from $m=2$ to $m=9$, in degrees per minute?
| $m$ | 0 | 2 | 5 | 9 |
|---|---|---|---|---|
| $T(m)$ | 340 | 346 | 358 | 361 |
- $3$
- $\frac{15}{7}$
- $\frac{7}{15}$
- $\frac{61}{9}$
Question 13 · Multiple choice
CED 1.2No calculatorThe graph of $y=g(x)$, where $g(x)=4-(x-2)^2$, is shown. What is the average rate of change of $g$ over $[0,3]$?
- $1$
- $3$
- $-1$
- $\frac{1}{3}$
Question 14 · Multiple choice
CED 1.2Graphing calculatorLet $g(x)=\sqrt{x^2+5}$. What is the average rate of change of $g$ over $[1,4]$?
- $2.133$
- $0.533$
- $1.000$
- $0.711$
Question 15 · Multiple choice
CED 1.2No calculatorThe population $P$ of a town, in thousands, is modeled by a function of time $t$ in years. The average rate of change of $P$ over $[2,6]$ is $3.5$ thousand people per year, and $P(2)=40$. What is $P(6)$?
- $43.5$
- $47$
- $54$
- $61$
Question 16 · Multiple choice
CED 1.2No calculatorFor $f(x)=x^2+kx$, the average rate of change of $f$ over $[1,3]$ is $10$. What is the value of $k$?
- $2$
- $10$
- $6$
- $8$
Question 17 · Multiple choice
CED 1.2Graphing calculatorLet $h(x)=2^x+x^2$. What is the average rate of change of $h$ over the interval $[0.5,2.5]$?
- $10.243$
- $6.786$
- $4.763$
- $5.121$
Question 18 · Multiple choice
CED 1.2Graphing calculatorLet $r(x)=\dfrac{3x+1}{x^2+2}$. What is the average rate of change of $r$ over $[1.3,\,3.7]$?
- $-0.232$
- $0.232$
- $-0.557$
- $-0.111$
Question 19 · Multiple choice
CED 1.2Graphing calculatorThe temperature of a liquid, in degrees Celsius, $t$ minutes into an experiment is modeled by $C(t)=0.02t^3-0.5t^2+4t+10$. What is the average rate of change of the temperature, in degrees per minute, from $t=2.5$ to $t=8.5$?
- $2.970$
- $0.495$
- $0.349$
- $0.315$
Question 20 · Multiple choice
CED 1.3No calculatorWhich type of function best fits the data in the table?
| $x$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $y$ | 5 | 8 | 13 | 20 | 29 |
- Linear
- Quadratic
- Exponential
- Cubic, but not quadratic
Question 21 · Multiple choice
CED 1.3No calculatorThe table gives values of a quadratic function $q$ at equally spaced inputs. What is $q(6)$?
| $x$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $q(x)$ | 5 | 8 | 13 | 20 | 29 |
- $40$
- $49$
- $47$
- $53$
Question 22 · Multiple choice
CED 1.3No calculatorA linear function $f$ has an average rate of change of $4$ over every interval, and $f(2)=7$. What is $f(10)$?
- $39$
- $32$
- $47$
- $40$
Question 23 · Multiple choice
CED 1.3No calculatorThe average rates of change of a quadratic function $f$ over $[0,1]$, $[1,2]$ and $[2,3]$ are $7$, $3$ and $-1$. What is the average rate of change of $f$ over $[3,4]$?
- $-5$
- $-1$
- $-4$
- $-3$
Question 24 · Multiple choice
CED 1.3No calculatorLet $f(x)=-2x^2+12x+1$. For any $k$, the average rate of change of $f$ over $[k+1,k+2]$ minus the average rate of change over $[k,k+1]$ is
- $-2$
- $12$
- $-4$
- $4$
Question 25 · Multiple choice
CED 1.3No calculatorA linear function $g$ has $g(-1)=4$ and $g(3)=-8$. Which of the following is $g(x)$?
- $-3x+4$
- $-3x+1$
- $3x+7$
- $-x+3$
Question 26 · Multiple choice
CED 1.3No calculatorA quadratic function $h$ has $h(0)=1$. Its average rate of change over $[0,2]$ is $6$, and over $[2,4]$ it is $-2$. What is the maximum value of $h$?
- $13$
- $\frac{25}{2}$
- $9$
- $\frac{27}{2}$
Question 27 · Multiple choice
CED 1.3Graphing calculatorA quadratic regression is fit to the data in the table. For the regression model, the average rates of change over consecutive intervals of length $1$ change by the same amount each time. To three decimal places, what is that amount?
| $x$ | 0 | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|---|
| $y$ | 2.1 | 3.0 | 5.2 | 8.9 | 13.7 | 20.1 |
- $0.677$
- $3.594$
- $1.354$
- $3.600$
Question 28 · Multiple choice
CED 1.3Graphing calculatorA linear regression is fit to the data in the table. To three decimal places, what is the rate of change of the regression line?
| $x$ | 2 | 4 | 6 | 8 | 10 |
|---|---|---|---|---|---|
| $y$ | 13.5 | 17.1 | 21.4 | 24.2 | 28.9 |
- $9.650$
- $0.528$
- $1.925$
- $1.895$
Question 29 · Multiple choice
CED 1.3Graphing calculatorA quadratic regression is fit to the data in the table. To three decimal places, what is the average rate of change of the regression model over $[2,5]$?
| $x$ | 0 | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|---|
| $y$ | 40.0 | 35.2 | 32.1 | 30.3 | 30.4 | 31.9 |
- $-0.038$
- $-0.067$
- $-0.114$
- $-1.620$
Question 30 · Multiple choice
CED 1.4No calculatorThe graph of the polynomial $p(x)=x^4-4x^2+2$ is shown. How many relative extrema does $p$ have?
- $2$
- $3$
- $4$
- $1$
Question 31 · Multiple choice
CED 1.4No calculatorThe graph of $p(x)=-x^3+3x+1$ is shown for $-2\le x\le 2$. What is the absolute maximum value of $p$ on $[-2,2]$?
- $3$
- $1$
- $5$
- $-1$
Question 32 · Multiple choice
CED 1.4No calculatorLet $p(x)=x^3-6x^2+5$. At what value of $x$ does the graph of $p$ have a point of inflection?
- $0$
- $4$
- $6$
- $2$
Question 33 · Multiple choice
CED 1.4No calculatorOn which interval is the graph of $q(x)=x^3+3x^2-9x$ concave down?
- $(-1,\infty)$
- $(-3,1)$
- $(-\infty,-1)$
- $(-\infty,-3)$
Question 34 · Multiple choice
CED 1.4No calculatorFor a function $f$, the average rates of change over $[0,1]$, $[1,2]$, $[2,3]$ and $[3,4]$ are $5$, $2$, $-1$ and $-4$. Which statement is consistent with this information?
- The graph of $f$ is concave down on $[0,4]$
- The graph of $f$ is concave up on $[0,4]$
- $f$ is linear on $[0,4]$
- $f$ is decreasing on $[0,4]$
Question 35 · Multiple choice
CED 1.4No calculatorWhat is the absolute maximum value of $p(x)=-x^4+8x^2-3$?
- $-3$
- $16$
- $29$
- $13$
Question 36 · Multiple choice
CED 1.4No calculatorWhat is the greatest number of relative extrema a polynomial function of degree $5$ can have?
- $5$
- $4$
- $3$
- $6$
Question 37 · Multiple choice
CED 1.4Graphing calculatorLet $p(x)=0.5x^3-2x^2-3x+7$. To three decimal places, what is the relative maximum value of $p$?
- $-0.610$
- $7.972$
- $-6.713$
- $7.000$
Question 38 · Multiple choice
CED 1.4Graphing calculatorThe graph of $q(x)=x^4-2x^3-5x^2+x$ has two points of inflection. To three decimal places, what is the $x$-coordinate of the one farther to the right?
- $-0.541$
- $2.471$
- $1.541$
- $-12.010$
Question 39 · Multiple choice
CED 1.4Graphing calculatorLet $p(x)=x^4-4.2x^2+x+3$. To three decimal places, what is the absolute minimum value of $p$ on the interval $[-2,2]$?
- $0.008$
- $-1.505$
- $0.200$
- $-2.888$
Question 40 · Multiple choice
CED 1.5No calculatorA polynomial $p$ with real coefficients has degree $4$. Two of its zeros are $2$ and $3+i$. Which of the following must also be a zero of $p$?
- $-3+i$
- $-2$
- $3-i$
- $-3-i$
Question 41 · Multiple choice
CED 1.5No calculatorLet $p(x)=(x-1)^2(x+3)^3$. Which statement describes the graph of $p$ at $x=-3$?
- It touches the $x$-axis without crossing
- It crosses the $x$-axis
- It has a vertical asymptote
- It does not meet the $x$-axis
Question 42 · Multiple choice
CED 1.5No calculatorHow many distinct real zeros does $p(x)=x^4-10x^2+9$ have?
- $2$
- $0$
- $3$
- $4$
Question 43 · Multiple choice
CED 1.5No calculatorFind every zero, real or nonreal, of the cubic $p(x)=x^3-3x^2+9x-27$.
- $3$ only
- $-3,\ 3i,\ -3i$
- $3,\ 3i,\ -3i$
- $3,\ -3,\ 3i$
Question 44 · Multiple choice
CED 1.5No calculatorWhich polynomial has zeros only at $x=1$ (multiplicity $2$) and $x=-4$ (multiplicity $1$), and leading coefficient $1$?
- $(x-1)^2(x+4)$
- $(x+1)^2(x-4)$
- $(x-1)(x+4)^2$
- $(x-1)(x+4)$
Question 45 · Multiple choice
CED 1.5No calculatorA polynomial of degree $6$ with real coefficients has exactly two distinct real zeros, each of multiplicity $1$. How many nonreal zeros does it have, counted with multiplicity?
- $4$
- $2$
- $6$
- $3$
Question 46 · Multiple choice
CED 1.5No calculatorFor what value of $k$ is $x+2$ a factor of $x^3+kx^2-4x-12$?
- $-3$
- $5$
- $1$
- $3$
Question 47 · Multiple choice
CED 1.5Graphing calculatorThe polynomial $p(x)=x^3+2x-7$ has exactly one real zero. To three decimal places, what is it?
- $1.569$
- $1.913$
- $3.500$
- $-1.569$
Question 48 · Multiple choice
CED 1.5Graphing calculatorTo three decimal places, what is the greatest real zero of $p(x)=x^4-5x^2+3x+1$?
- $-2.461$
- $1.700$
- $1.000$
- $2.236$
Question 49 · Multiple choice
CED 1.5Graphing calculatorThe polynomial $p(x)=2x^3-x^2-8x+3$ has one zero between $x=1$ and $x=3$. To three decimal places, what is that zero?
- $0.371$
- $-1.948$
- $2.078$
- $1.500$
Question 50 · Multiple choice
CED 1.6No calculatorFind $\displaystyle\lim_{x\to-\infty}\left(4x^2-3x^5\right)$.
- $-\infty$
- $\infty$
- $-2$
- $0$
Question 51 · Multiple choice
CED 1.6No calculatorWhich describes the end behavior of $p(x)=(3-x)(x+1)^2(2x-1)$?
- $\lim_{x\to-\infty}p(x)=\infty$ and $\lim_{x\to\infty}p(x)=\infty$
- $\lim_{x\to-\infty}p(x)=-\infty$ and $\lim_{x\to\infty}p(x)=\infty$
- $\lim_{x\to-\infty}p(x)=-\infty$ and $\lim_{x\to\infty}p(x)=-\infty$
- $\lim_{x\to-\infty}p(x)=\infty$ and $\lim_{x\to\infty}p(x)=-\infty$
Question 52 · Multiple choice
CED 1.6, 1.5No calculatorThe graph of a polynomial $p$ is shown. Which of the following could be $p(x)$?
- $-(x+2)(x-1)^2$
- $(x+2)(x-1)^2$
- $(x-2)(x+1)^2$
- $(x+2)^2(x-1)$
Question 53 · Multiple choice
CED 1.6No calculatorA polynomial $p$ satisfies $\displaystyle\lim_{x\to-\infty}p(x)=-\infty$ and $\displaystyle\lim_{x\to\infty}p(x)=-\infty$. Which of the following could be $p(x)$?
- $-x^4+x$
- $x^3-5$
- $-x^3$
- $2x^4$
Question 54 · Multiple choice
CED 1.6No calculatorWhat is $\displaystyle\lim_{x\to\infty}\frac{(2x-1)^3(4-x^2)}{x^5}$?
- $8$
- $-2$
- $-8$
- $4$
Question 55 · Multiple choice
CED 1.6No calculatorLet $f(x)=0.01x^3-50x^2$. What is $\displaystyle\lim_{x\to\infty}f(x)$?
- $-\infty$
- $0$
- $-50$
- $\infty$
Question 56 · Multiple choice
CED 1.6, 1.5No calculatorLet $p(x)=x^4-30x^3$. What is the least number $N$ such that $p(x)>0$ for all $x>N$?
- $29$
- $31$
- $0$
- $30$
Question 57 · Multiple choice
CED 1.6No calculatorWhich statement about $g(x)=-3x^6+100x^5$ is true?
- $g(x)\to\infty$ as $x\to\infty$ and as $x\to-\infty$
- $g(x)\to\infty$ as $x\to\infty$, and $g(x)\to-\infty$ as $x\to-\infty$
- $g(x)\to-\infty$ as $x\to\infty$ and as $x\to-\infty$
- $g(x)\to-\infty$ as $x\to\infty$, and $g(x)\to\infty$ as $x\to-\infty$
Question 58 · Multiple choice
CED 1.6Graphing calculatorLet $p(x)=0.05x^4-2x$ and $q(x)=3x^3+10$. As $x\to\infty$, $p(x)$ eventually exceeds $q(x)$: there is a number $c$ such that $p(x)>q(x)$ for every $x>c$, and $p(c)=q(c)$. To three decimal places, what is $c$?
- $60.000$
- $20.000$
- $15.000$
- $60.012$
Question 59 · Multiple choice
CED 1.7No calculatorWhat is the horizontal asymptote of the graph of $r(x)=\dfrac{6x^2-1}{3x^2+x}$?
- $y=2$
- $y=6$
- $y=\frac{1}{3}$
- $y=0$
Question 60 · Multiple choice
CED 1.7No calculatorWhat is $\displaystyle\lim_{x\to\infty}\frac{4x^3-x}{2x^2+7}$?
- $2$
- $\infty$
- $0$
- $-\infty$
Question 61 · Multiple choice
CED 1.7, 1.11No calculatorWhich line is a slant asymptote of the graph of $r(x)=\dfrac{x^2+3x+1}{x-1}$?
- $y=x+3$
- $y=x+4$
- $y=x-4$
- $y=x+2$
Question 62 · Multiple choice
CED 1.7No calculatorWhat is $\displaystyle\lim_{x\to-\infty}\frac{5-2x}{x+3}$?
- $\frac{5}{3}$
- $2$
- $-\infty$
- $-2$
Question 63 · Multiple choice
CED 1.7No calculatorWhich of the following functions has a graph with horizontal asymptote $y=0$?
- $\frac{x^2+1}{x^2-4}$
- $\frac{x^3}{x^2+1}$
- $\frac{x+1}{x^2-4}$
- $\frac{2x}{x-4}$
Question 64 · Multiple choice
CED 1.7No calculatorThe graph of $r(x)=\dfrac{ax^2+5}{2x^2-x}$ has horizontal asymptote $y=3$. What is $a$?
- $6$
- $3$
- $\frac{3}{2}$
- $5$
Question 65 · Multiple choice
CED 1.7Graphing calculatorLet $r(x)=\dfrac{2x^2+1}{x^2+x+3}$. Its graph has the horizontal asymptote $y=2$, but $r$ takes values above $2$. To three decimal places, what is the maximum value of $r$?
- $2.217$
- $2.000$
- $-5.098$
- $0.328$
Question 66 · Multiple choice
CED 1.7Graphing calculatorLet $r(x)=\dfrac{5x^2-3x}{x^2+1}$, whose graph has horizontal asymptote $y=5$. For large $x>0$, $r(x)$ is close to $5$. To three decimal places, what is the greatest $x$ for which $r(x)=4.9$?
- $-1.553$
- $31.553$
- $8.888$
- $49.000$
Question 67 · Multiple choice
CED 1.8No calculatorFind every value of $x$ at which $r(x)=\dfrac{x^2-16}{x^2+x-12}$ equals $0$.
- $x=4$ and $x=-4$
- $x=4$ only
- $x=-4$ only
- $x=3$ and $x=4$
Question 68 · Multiple choice
CED 1.8No calculatorFor which values of $x$ is $\dfrac{(x-1)(x+4)}{x-3}\ge0$?
- $(-\infty,-4]\cup[1,3)$
- $[-4,1]\cup[3,\infty)$
- $[-4,1]\cup(3,\infty)$
- $[1,3)$
Question 69 · Multiple choice
CED 1.8No calculatorWhat is the $x$-intercept of the graph of $r(x)=\dfrac{2x+5}{x^2+1}$?
- $-\frac{5}{2}$
- $\frac{5}{2}$
- $-\frac{2}{5}$
- $5$
Question 70 · Multiple choice
CED 1.8No calculatorWhich function has zeros at $x=-1$ and $x=4$ and at no other $x$?
- $\frac{(x+1)(x-4)}{x-4}$
- $\frac{(x-1)(x+4)}{x+2}$
- $\frac{(x+1)(x-4)}{x^2-1}$
- $\frac{(x+1)(x-4)}{x-2}$
Question 71 · Multiple choice
CED 1.8No calculatorFor which values of $x$ is $\dfrac{x^2-4x}{x^2-16}<0$?
- $(-4,0)$
- $(-4,0)\cup(0,4)$
- $(0,4)$
- $(-\infty,-4)$
Question 72 · Multiple choice
CED 1.8No calculatorLet $r(x)=\dfrac{(x-2)^2(x+1)}{(x-5)(x+3)}$. At which zero of $r$ does $r(x)$ not change sign?
- $x=-1$
- $x=2$
- $x=5$
- $x=-3$
Question 73 · Multiple choice
CED 1.8No calculatorFind every value of $x$ at which $r(x)=\dfrac{x^3-4x}{x^2+4x+4}$ equals $0$.
- $x=-2$, $x=0$ and $x=2$
- $x=0$ only
- $x=0$ and $x=2$
- $x=-2$ and $x=2$
Question 74 · Multiple choice
CED 1.8Graphing calculatorTo three decimal places, what is the greatest zero of $r(x)=\dfrac{x^3-3x+1}{x^2+4}$?
- $0.347$
- $-1.879$
- $1.532$
- $2.000$
Question 75 · Multiple choice
CED 1.8Graphing calculatorThe function $r(x)=\dfrac{x^3-2x-5}{x-1}$ has exactly one real zero. To three decimal places, what is it?
- $1.000$
- $-2.095$
- $1.710$
- $2.095$
Question 76 · Multiple choice
CED 1.9No calculatorFind all the vertical asymptotes of the graph of $y=\dfrac{x+3}{x^2-x-12}$.
- $x=-3$ and $x=4$
- $x=-3$ only
- There are none
- $x=4$ only
Question 77 · Multiple choice
CED 1.9No calculatorAs $x$ approaches $3$ from the left, what does $\dfrac{x+2}{x-3}$ approach?
- $\infty$
- $-\infty$
- $5$
- $0$
Question 78 · Multiple choice
CED 1.9No calculatorWhat is $\displaystyle\lim_{x\to-1}\frac{1}{(x+1)^2}$?
- $-\infty$
- $0$
- $\infty$
- $1$
Question 79 · Multiple choice
CED 1.9No calculatorLet $r(x)=\dfrac{x-1}{(x-4)^2(x+2)}$. Which statement about the behavior of $r$ near $x=4$ is true?
- $r(x)\to-\infty$ as $x\to4^-$ and $r(x)\to\infty$ as $x\to4^+$
- $r(x)\to\infty$ as $x\to4^-$ and $r(x)\to-\infty$ as $x\to4^+$
- $r(x)\to-\infty$ as $x\to4^-$ and as $x\to4^+$
- $r(x)\to\infty$ as $x\to4^-$ and as $x\to4^+$
Question 80 · Multiple choice
CED 1.9, 1.10No calculatorWhich function has a vertical asymptote at $x=3$ and a hole at $x=-1$?
- $\frac{x+1}{(x+1)(x-3)}$
- $\frac{x-1}{(x+1)(x-3)}$
- $\frac{(x+1)(x-3)}{x+1}$
- $\frac{x-3}{(x+1)(x-3)}$
Question 81 · Multiple choice
CED 1.9, 1.7No calculatorThe graph of a rational function $r$ is shown, with its asymptotes dashed. Which of the following could be $r(x)$?
- $\frac{2x}{x+1}$
- $\frac{2x}{x-1}$
- $\frac{x}{x-1}$
- $\frac{2(x-1)}{x}$
Question 82 · Multiple choice
CED 1.9No calculatorWhat is $\displaystyle\lim_{x\to3^+}\frac{x^2-9}{x^2-6x+9}$?
- $-\infty$
- $1$
- $\infty$
- $6$
Question 83 · Multiple choice
CED 1.9Graphing calculatorThe graph of $r(x)=\dfrac{x+1}{x^3-x-3}$ has exactly one vertical asymptote. To three decimal places, what is its $x$-coordinate?
- $1.672$
- $-1.000$
- $3.000$
- $1.442$
Question 84 · Multiple choice
CED 1.9Graphing calculatorThe graph of $r(x)=\dfrac{2x-1}{x^2-3.4x+1.7}$ has two vertical asymptotes. To three decimal places, what is the $x$-coordinate of the one farther to the right?
- $0.609$
- $2.791$
- $0.500$
- $1.700$
Question 85 · Multiple choice
CED 1.10No calculatorThe graph of $r(x)=\dfrac{x^2-4}{x^2-x-2}$ has a hole. What is the $y$-coordinate of the hole?
- $0$
- $2$
- $-\frac{4}{3}$
- $\frac{4}{3}$
Question 86 · Multiple choice
CED 1.10No calculatorWhich function has a hole in its graph at $x=5$?
- $\frac{x^2-25}{x-5}$
- $\frac{x+5}{x^2-25}$
- $\frac{x}{x-5}$
- $\frac{x^2+5}{x+5}$
Question 87 · Multiple choice
CED 1.10No calculatorThe graph of $r(x)=\dfrac{x^2+2x-15}{x^2-9}$ has one hole. Where is it?
- $\left(3,\frac{4}{3}\right)$
- $\left(-3,\frac{1}{3}\right)$
- $\left(3,0\right)$
- $\left(-5,0\right)$
Question 88 · Multiple choice
CED 1.10No calculatorThe graph of $g(x)=\dfrac{x^2+kx+6}{x+2}$ has a hole at $x=-2$. What is $k$?
- $-5$
- $5$
- $3$
- $6$
Question 89 · Multiple choice
CED 1.10No calculatorThe graph of $f(x)=\dfrac{x^3-1}{x-1}$ has a hole at $x=1$. What is the $y$-coordinate of the hole?
- $0$
- $1$
- $2$
- $3$
Question 90 · Multiple choice
CED 1.10, 1.8No calculatorLet $r(x)=\dfrac{(x+3)^2}{(x+3)(x-1)}$. Which statement about the graph of $r$ at $x=-3$ is true?
- It has a vertical asymptote $x=-3$
- It crosses the $x$-axis at $(-3,0)$
- It has a hole at $(-3,0)$
- It has a hole at $\left(-3,\frac{3}{2}\right)$
Question 91 · Multiple choice
CED 1.11No calculatorFor $x\ne1$, which expression is equal to $\dfrac{3x^3-7x^2+9x-4}{x-1}$?
- $3x^2-4x+5-\frac{1}{x-1}$
- $3x^2-10x+19-\frac{23}{x-1}$
- $3x^2-4x+5+\frac{1}{x-1}$
- $3x^2-4x+6$
Question 92 · Multiple choice
CED 1.11No calculatorWhat is the coefficient of $x^3$ in the expansion of $(2x-1)^5$?
- $-80$
- $40$
- $10$
- $80$
Question 93 · Multiple choice
CED 1.11No calculatorWhat is the coefficient of $x^2$ in the expansion of $(x-3)^4$?
- $54$
- $-54$
- $6$
- $-108$
Question 94 · Multiple choice
CED 1.11No calculatorWhich is a factored form of $x^3-27$?
- $(x-3)(x^2-3x+9)$
- $(x-3)(x^2+3x+9)$
- $(x-3)^3$
- $(x+3)(x^2-3x+9)$
Question 95 · Multiple choice
CED 1.11, 1.5No calculatorWhich form of $p(x)=2x^2+2x-12$ shows its zeros directly?
- $2(x-3)(x+2)$
- $2(x+3)(x-2)$
- $(2x-4)(x+2)$
- $2\left(x+\frac{1}{2}\right)^2-12$
Question 96 · Multiple choice
CED 1.11No calculatorSimplify $\dfrac{x^2+7x+12}{x^2-16}$ for $x\ne\pm4$.
- $\frac{x+3}{x-4}$
- $\frac{x+3}{x+4}$
- $\frac{x+4}{x-3}$
- $\frac{7x+12}{-16}$
Question 97 · Multiple choice
CED 1.11, 1.5No calculatorWhen $p(x)=x^4+3x^3-7x+1$ is divided by $x+2$, what is the remainder?
- $-7$
- $15$
- $7$
- $-33$
Question 98 · Multiple choice
CED 1.11No calculatorWhich expression is equivalent to $\dfrac{3x^2+2x}{x+1}$ for $x\ne-1$?
- $3x+1-\frac{1}{x+1}$
- $3x-1-\frac{1}{x+1}$
- $3x+5+\frac{5}{x+1}$
- $3x-1+\frac{1}{x+1}$
Question 99 · Multiple choice
CED 1.11No calculatorWhich expression is equivalent to $(1+x)^3-(1-x)^3$?
- $6x$
- $2x^3$
- $6x^2+2$
- $2x^3+6x$
Question 100 · Multiple choice
CED 1.12No calculatorIf $f(x)=x^2$, where is the vertex of the graph of $y=f(x+4)-5$?
- $\left(4,-5\right)$
- $\left(-5,-4\right)$
- $\left(-4,-5\right)$
- $\left(-4,5\right)$
Question 101 · Multiple choice
CED 1.12No calculatorThe domain of $f$ is $[-2,6]$. What is the domain of $g(x)=f(2x)$?
- $[-4,12]$
- $[-1,3]$
- $[0,8]$
- $[-2,6]$
Question 102 · Multiple choice
CED 1.12No calculatorThe range of $f$ is $[1,5]$. What is the range of $g(x)=-2f(x)+3$?
- $[-7,1]$
- $[1,13]$
- $[-7,-1]$
- $[-1,7]$
Question 103 · Multiple choice
CED 1.12No calculatorThe point $(2,5)$ is on the graph of $y=f(x)$. Which point must be on the graph of $y=3f(x+1)$?
- $\left(3,15\right)$
- $\left(1,8\right)$
- $\left(1,15\right)$
- $\left(3,6\right)$
Question 104 · Multiple choice
CED 1.12No calculatorThe graph of $f(x)=|x|$ is reflected over the $x$-axis, then translated $4$ units left and $1$ unit up. Which is the new function?
- $-|x+4|+1$
- $-|x-4|+1$
- $|x+4|-1$
- $-|x+4|-1$
Question 105 · Multiple choice
CED 1.12No calculatorLet $f(x)=x^3$ and $g(x)=8x^3$. For what value of $b$ is $g(x)=f(bx)$ for all $x$?
- $8$
- $\frac{1}{2}$
- $\frac{1}{8}$
- $2$
Question 106 · Multiple choice
CED 1.12No calculatorWhat is the vertex of the graph of $h(x)=-2(x+1)^2+7$?
- $\left(1,7\right)$
- $\left(-1,7\right)$
- $\left(-1,-7\right)$
- $\left(-2,7\right)$
Question 107 · Multiple choice
CED 1.12No calculatorThe table gives values of $f$. Let $g(x)=f(x-1)-4$. What is $g(2)$?
| $x$ | -1 | 0 | 1 | 2 |
|---|---|---|---|---|
| $f(x)$ | 3 | 5 | 2 | 0 |
- $-4$
- $1$
- $-3$
- $-2$
Question 108 · Multiple choice
CED 1.12Graphing calculatorLet $f(x)=x^3-5x$ and $g(x)=f\big(2(x-1)\big)+3$. To three decimal places, what is the $x$-coordinate of the relative minimum of $g$?
- $1.291$
- $3.582$
- $1.645$
- $0.645$
Question 109 · Multiple choice
CED 1.12Graphing calculatorLet $f(x)=x^4-3.5x^2+x$ and $h(x)=-0.5f(x+2)$. To three decimal places, what is the absolute maximum value of $h$?
- $-4.419$
- $0.889$
- $8.839$
- $2.210$
Question 110 · Multiple choice
CED 1.13No calculatorWhich type of function is most appropriate to model the data in the table?
| $x$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $y$ | 2.0 | 3.9 | 6.1 | 7.9 | 10.1 |
- Quadratic with a negative leading coefficient
- Cubic
- Linear
- Rational with a vertical asymptote
Question 111 · Multiple choice
CED 1.13No calculatorThe table gives the number of different handshakes $H$ when each of $n$ people shakes hands once with each other person. Which type of function models $H$ exactly?
| $n$ | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| $H$ | 0 | 1 | 3 | 6 | 10 |
- Linear
- Quadratic
- Exponential
- Cubic
Question 112 · Multiple choice
CED 1.13No calculatorA drone's height $h$, in meters, is recorded every second. Which type of model fits these data exactly?
| $t$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $h$ | 0 | 30 | 40 | 30 | 0 |
- Quadratic
- Linear
- Exponential
- Cubic, but not quadratic
Question 113 · Multiple choice
CED 1.13, 1.14No calculatorAn open box is made from a $12$-inch by $12$-inch sheet by cutting a square of side $x$ inches from each corner and folding up the sides. Its volume is $V(x)=x(12-2x)^2$. What domain makes sense for this model?
- $(0,12)$
- $[0,\infty)$
- $(0,3)$
- $(0,6)$
Question 114 · Multiple choice
CED 1.13, 1.7No calculatorThe average cost per item, in dollars, of making $n$ items is $C(n)=\dfrac{500+4n}{n}$. As $n$ increases without bound, what value does $C(n)$ approach?
- $0$
- $4$
- $500$
- $504$
Question 115 · Multiple choice
CED 1.13No calculatorWhich type of function fits the data in the table exactly?
| $x$ | 0 | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|
| $y$ | 2 | 5 | 18 | 49 | 106 |
- Quadratic
- Linear
- Cubic
- Exponential
Question 116 · Multiple choice
CED 1.13Graphing calculatorA cubic regression $y=ax^3+bx^2+cx+d$ is fit to the data in the table. To three decimal places, what is $a$?
| $x$ | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| $y$ | 2.0 | 4.9 | 6.1 | 6.8 | 9.2 | 14.5 |
- $0.274$
- $0.300$
- $2.174$
- $-2.578$
Question 117 · Multiple choice
CED 1.13Graphing calculatorThe data in the table decrease and then increase, so a quadratic model is chosen. Use a quadratic regression to predict $y$ when $x=7.5$.
| $x$ | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| $y$ | 30.2 | 26.1 | 24.0 | 23.8 | 25.9 | 29.7 |
- $26.240$
- $39.393$
- $35.670$
- $26.617$
Question 118 · Multiple choice
CED 1.13Graphing calculatorThe data in the table are roughly linear. Use a linear regression to predict $y$ when $x=10$.
| $x$ | 1 | 3 | 4 | 6 | 8 |
|---|---|---|---|---|---|
| $y$ | 4.2 | 8.1 | 10.3 | 13.6 | 18.0 |
- $21.880$
- $22.900$
- $21.737$
- $19.459$
Question 119 · Multiple choice
CED 1.14No calculatorA quadratic model passes through $(0,4)$, $(1,7)$ and $(2,14)$. What does the model predict at $x=5$?
- $59$
- $39$
- $64$
- $54$
Question 120 · Multiple choice
CED 1.14Graphing calculatorUse a quadratic regression on the data in the table to predict $y$ when $x=7$.
| $x$ | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| $y$ | 3.1 | 5.8 | 10.9 | 18.2 | 27.0 |
- $49.130$
- $45.420$
- $55.780$
- $51.480$
Question 121 · Multiple choice
CED 1.14No calculatorA phone plan costs $C(m)=20$ dollars for $0\le m\le100$ minutes and $C(m)=20+0.15(m-100)$ dollars for $m>100$. What is $C(240)$?
- $41$
- $36$
- $56$
- $21$
Question 122 · Multiple choice
CED 1.14Graphing calculatorUse a linear regression on the data in the table to predict $y$ when $x=12$.
| $x$ | 2 | 4 | 6 | 8 | 10 |
|---|---|---|---|---|---|
| $y$ | 7.1 | 10.8 | 15.2 | 18.9 | 23.0 |
- $27.500$
- $25.880$
- $26.970$
- $28.100$
Question 123 · Multiple choice
CED 1.14, 1.4No calculatorA company's monthly profit, in thousands of dollars, is modeled by $P(t)=-0.5t^2+6t+20$ for $0\le t\le12$, where $t$ is months since a product launch. At what time is the modeled profit greatest?
- $t=12$
- $t=6$
- $t=3$
- $t=20$
Question 124 · Multiple choice
CED 1.14No calculatorThe volume of water in a tank, in gallons, is modeled by $V(t)=1200-80t$, where $t$ is hours after a drain is opened. Which domain is appropriate for this model?
- $[0,1200]$
- $[0,\infty)$
- $[0,15]$
- $[15,\infty)$
Question 125 · Multiple choice
CED 1.14Graphing calculatorAn open box is made from a $20$-inch by $14$-inch sheet of cardboard by cutting a square of side $x$ inches from each corner and folding up the sides, so $V(x)=x(20-2x)(14-2x)$ for $0<x<7$. To three decimal places, what is the greatest possible volume, in cubic inches?
- $2.704$
- $336.000$
- $333.926$
- $339.013$
Question 126 · Multiple choice
CED 1.14Graphing calculatorThe table shows a company's monthly sales, in thousands of dollars, $x$ months after a product launch. Use a cubic regression to predict the sales when $x=5.5$.
| $x$ (months) | 0 | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|---|
| Sales | 5.0 | 8.2 | 9.1 | 9.9 | 12.8 | 20.1 |
- $26.069$
- $21.669$
- $18.573$
- $33.967$
Question 127 · Multiple choice
CED 1.14Graphing calculatorA company's monthly profit, in thousands of dollars, is modeled by $P(x)=-0.02x^3+0.9x^2+5x-40$ for $0\le x\le40$, where $x$ is the number of units sold, in hundreds. To three decimal places, how many hundred units maximize the profit?
- $386.566$
- $32.559$
- $15.000$
- $30.000$
Question 128 · Free response (6 points) · Function concepts
CED 1.1, 1.2, 1.4, 1.5Graphing calculatorFRQ type 1Let $f(x)=x^3-6x^2+4x+5$. A graphing calculator is allowed.
- (A(i)) Find the average rate of change of $f$ over $[0,3]$. [1 point]
- (A(ii)) Find all real zeros of $f$. Give decimal answers correct to three places. [1 point]
- (B) Find the interval on which $f$ is decreasing. Give a reason for your answer. [2 points]
- (C) Use the average rates of change of $f$ over $[0,0.5]$ and over $[0.5,1]$ to decide whether the rate of change of $f$ is increasing or decreasing on $[0,1]$. What does this tell you about the graph of $f$ there? [2 points]
Question 129 · Free response (6 points) · Modeling a non-periodic context
CED 1.3, 1.13, 1.14, 1.2Graphing calculatorFRQ type 2A ball is launched upward from a platform. Its height $h$, in feet, above the ground was recorded every half second, as shown in the table. A graphing calculator is allowed.
| $t$ (seconds) | 0 | 0.5 | 1 | 1.5 |
|---|---|---|---|---|
| $h(t)$ (feet) | 6 | 22 | 30 | 30 |
- (A(i)) Find the average rates of change of $h$ over $[0,0.5]$, $[0.5,1]$ and $[1,1.5]$, and explain why a quadratic model is appropriate. [1 point]
- (A(ii)) Find the quadratic function $h(t)=at^2+bt+c$ that fits all four data points exactly. [1 point]
- (B(i)) Use the model to find the time when the ball reaches the ground. Give your answer correct to three decimal places. [1 point]
- (B(ii)) Find the average rate of change of $h$ over $[0,2]$, with units. [1 point]
- (C) Find $h(3)$ from the model and use it to explain why the model is not valid at $t=3$. [2 points]
Question 130 · Free response (6 points) · Function concepts
CED 1.7, 1.8, 1.9, 1.10Graphing calculatorFRQ type 1Let $r(x)=\dfrac{2x^2-2x-12}{x^2-4x+3}$. A graphing calculator is allowed.
- (A(i)) Find the $x$-coordinate of each vertical asymptote and of each hole in the graph of $r$. [1 point]
- (A(ii)) Find the coordinates of the hole. [1 point]
- (B) Find $\displaystyle\lim_{x\to\infty}r(x)$ and $\displaystyle\lim_{x\to1^+}r(x)$. [2 points]
- (C) Find all values of $x$ for which $r(x)\ge0$. [2 points]
Question 131 · Free response (6 points) · Modeling a non-periodic context
CED 1.14, 1.13, 1.7, 1.2Graphing calculatorFRQ type 2A tank holds $40$ liters of a salt solution containing $12$ grams of salt. A solution with $0.8$ gram of salt per liter is pumped in. After $t$ liters have been added, the concentration of salt in the tank, in grams per liter, is modeled by $C(t)=\dfrac{12+0.8t}{40+t}$. A graphing calculator is allowed.
- (A(i)) Find $C(10)$ and say what it means in context. [1 point]
- (A(ii)) Find the average rate of change of $C$ over $[0,20]$. Give units. [1 point]
- (B) Find $\displaystyle\lim_{t\to\infty}C(t)$ and explain what it means in context. [2 points]
- (C) How many liters must be added for the concentration to reach $0.6$ gram per liter? [2 points]
Unit done? Sit a full AP Precalculus practice exam. Taking the SAT too? SAT Math: Algebra uses this unit.