Question 1
| x | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|
| f(x) | −17 | −27 | −39 | −53 | −69 | −87 |
The table gives values for the function f at selected values of x. Which of the following conclusions with reason is consistent with the values in the table?
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Why
The first differences are −10, −12, −14, −16, −18. Because the input intervals all have length 1, these are also the average rates of change. They are decreasing, so the slopes become more negative as x increases. Decreasing slopes mean the graph is concave down. The correct answer is the choice stating the graph is concave down because the average rate of change is decreasing.
Question 2
The graph of the function f is shown. What is the average rate of change of f on the interval −3 ≤ x ≤ 3, if it exists?
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Why
Average rate of change is the slope of the secant line: [f(3)−f(−3)]/[3−(−3)]. The graph gives f(−3)=3 and f(3)=3, so the numerator is 0. The average rate of change is 0.
Question 3
A student starts to drive to school from home in a straight line and quickly realizes they forgot their backpack. The student stops the car and then drives back to their starting position at home. Which graph could model the velocity v, in miles per hour, of the car as a function of time t, in hours? (Assume driving away from home involves positive velocity.)
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Why
The student initially drives away from home, so velocity is positive. The student stops, so velocity reaches 0. Then the student drives back toward home, so velocity is negative, and finally stops again at home. Graph A shows positive → 0 → negative → 0.
Question 4
The graph of a polynomial function y=p(x) is shown. Which of the following expressions could define p(x)?
🔒 Explanation locked until you answer
Why
The graph touches and turns at x=−3 and x=2 rather than crossing the x-axis. Both zeros therefore have even multiplicity. The matching factors are (x+3)² and (x−2)².
Question 5
The graph of a function models the percentage of charge C in a phone battery over a period of time t, in hours. Based on the graph, which collection of statements about the function and scenario is accurate?
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Why
The graph falls the entire time, so the function is always decreasing. But its steepness changes, so the battery is not losing charge at one constant rate. It is decreasing at different rates at different times.
Question 6
The polynomial function P is given by P(x)=(x−3)(x−2)(x+1), and the domain of P is −5 ≤ x ≤ 5. Which of the following is true about the graph of P?
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Why
The zeros are x=−1, 2, and 3. A cubic with three distinct real zeros has two local extrema between consecutive zeros. Because the domain is the closed interval [−5,5], absolute extrema exist; here they occur at the endpoints, while the two interior turning points are local but not global.
Question 7
A linear function P is used to model the price, in dollars, of used cars as a function of their age t, in years. It is known that P(4)=7300 and P(7)=5500. Based on this model, which of the following is true?
🔒 Explanation locked until you answer
Why
For a linear model, compute the constant slope: (5500−7300)/(7−4)=−1800/3=−600 dollars per year. So the price decreases by about $600 each year.
Question 8
Which of the following functions has the end behaviors limx→−∞ p(x)=−∞ and limx→∞ p(x)=∞?
🔒 Explanation locked until you answer
Why
Left down/right up is the end behavior of an odd-degree polynomial with positive leading coefficient. The matching option is the degree-3 product (x−10)(x+2)(x+3), whose leading term is x³.
Question 9
The graph of the function f is shown. On which of the following intervals is the graph of f increasing?
🔒 Explanation locked until you answer
Why
Reading left to right, the graph rises until the relative maximum near x=−4, falls until the relative minimum near x=0, and then rises again. Thus f is increasing on (−∞,−4) and (0,∞).
Question 10
The function f is given by f(x)=x³+x. Which statement is true and supports the claim that f is an odd function and not an even function?
🔒 Explanation locked until you answer
Why
f(−x)=−x³−x=−(x³+x)=−f(x), which is exactly the definition of an odd function. Therefore f(−3)=−f(3).
Question 11
A new special attraction opened at a museum. The museum management tracked the number of people who visited the attraction each day and created a function model M for the number of people for each day d after the attraction opened. Each day they also calculated the rate of change of the number of people visiting the attraction. They created a function model R for the rate of change, in people per day, for each day d after the attraction opened. The function R is given by R(d)=1/200(−d⁴+35d³−411d²+1845d−2686.5). At which of the following values of d does the graph of y=M(d) have a point of inflection?
🔒 Explanation locked until you answer
Why
R is the rate of change of M, so R=M′. Points of inflection of M occur where M′ changes from increasing to decreasing or vice versa—that is, at local extrema of R. The listed extrema occur at about d=3.894, 8.627, and 13.728, so all three values are points of inflection of M.
Question 12
The polynomial function is given by p(x)=(x−3)⁷(x+2)⁵(x²+ax+9), where a is an integer. For p, which statement is true about the multiplicity of the zero x=3?
🔒 Explanation locked until you answer
Why
The first factor contributes multiplicity 7. If a=−6, then x²−6x+9=(x−3)², which adds multiplicity 2 for a total multiplicity of 9.
Question 13
The graph of the function f is shown. Over which of the following intervals is f increasing?
🔒 Explanation locked until you answer
Why
The graph rises from x=−6 to −4, is constant from −4 to 0, decreases from 0 to 2, and rises again from 2 to 5. So f is increasing on [−6,−4] and [2,5].
Question 14
The polynomial function p is given by p(x)=x³−10x²−4. Which of the following describes the behavior of p as the input values decrease without bound?
🔒 Explanation locked until you answer
Why
The leading term x³ controls end behavior. As x→−∞, x³→−∞, so p(x) decreases without bound.
Question 15
The polynomial function f is given by f(x)=axᵇ, where a is an integer and b is a positive integer. It is known that limx→−∞f(x)=−∞ and limx→∞f(x)=−∞. Which statement must be true?
🔒 Explanation locked until you answer
Why
Both ends go in the same direction, so the exponent b must be even. Since both ends go downward, a is negative as well, but the statement that must be true among the choices is the one saying b must be even because the end behaviors are the same.
Question 16
The average rate of change of the function g on the interval (−1,3) is negative. Which of the following could be the graph of g?
🔒 Explanation locked until you answer
Why
A negative average rate of change means [g(3)−g(−1)]/[3−(−1)]<0. The denominator is positive, so we need g(3)
Question 17
The graph of the function f and a point labeled A on the graph are shown. Which statement about the graph of f at point A is true?
🔒 Explanation locked until you answer
Why
At A the curve is rising, so the instantaneous rate of change is positive. The slope is becoming less positive as the graph approaches a local maximum, so the graph is concave down. The correct choice is the one describing a positive rate of change and a concave-down graph.
Question 18
The function h is given by h(x)=−x⁴+x³+202x². Which of the following statements is true?
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Why
The leading term is −x⁴, so h(x)→−∞ as x→±∞. Therefore h has a global maximum, not a global minimum. The larger peak occurs for a critical point between x=0 and x=5, so h has a global maximum on that interval.