Candidates Test
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AP Calculus AB › Candidates Test
A continuous function $u$ on $0,5$ has candidates $x=0,1,4,5$ with $u(0)=3,u(1)=2,u(4)=4,u(5)=1$. Where is the absolute maximum?
$x=1$
$x=0$ (endpoint)
$x=4$
$x=5$
$x=0$
Explanation
This question demonstrates the Candidates Test for finding the absolute maximum on [0,5]. The candidates for absolute extrema are endpoints (x = 0, 5) and critical points (x = 1, 4). Evaluating the function at all candidates: u(0) = 3, u(1) = 2, u(4) = 4, and u(5) = 1. The largest value is u(4) = 4, so the absolute maximum occurs at x = 4. Choice E incorrectly focuses only on the endpoint x = 0, missing that critical points in the interior can yield larger values. The candidates algorithm is systematic: identify all endpoints and critical points, evaluate the function at each candidate, then select the location(s) with the most extreme values.
A continuous function $v$ on $-2,2$ has candidates $x=-2,-1,1,2$ with $v(-2)=0,v(-1)=-4,v(1)=-3,v(2)=-5$. Where is the absolute minimum?
$x=-2$
$x=-1$
$x=2$
$x=1$
$x=-1$ (critical point)
Explanation
This problem uses the Candidates Test to find the absolute minimum on [-2,2]. The candidates include endpoints (x = -2, 2) and critical points (x = -1, 1). Evaluating at all candidates: v(-2) = 0, v(-1) = -4, v(1) = -3, and v(2) = -5. The smallest value is v(2) = -5, so the absolute minimum occurs at x = 2. Choice E incorrectly assumes the minimum must occur at a critical point where v'(x) = 0, but endpoints can be extrema without having horizontal tangents. The candidates method ensures we find all absolute extrema: list endpoints and critical points, evaluate at each, then identify the most extreme values.
A continuous function $h$ on $-5,5$ has critical points $x=-4,1$. If $h(-5)=0,h(-4)=3,h(1)=2,h(5)=4$, where is the absolute maximum?
At $x=-5$
At $x=-5$ only
At $x=1$
At $x=-4$
At $x=5$
Explanation
The Candidates Test is a method in calculus to find the absolute maximum and minimum values of a continuous function on a closed interval. To apply this test, first identify all critical points within the interval where the derivative is zero or undefined. Then, evaluate the function at these critical points and at the endpoints of the interval. By comparing these function values, you can determine the absolute extrema, as they must occur at one of these candidate points. A tempting distractor is choice B, at x=-4, because h(-4)=3 is high but not the maximum, which is h(5)=4 at the endpoint. Always remember the transferable candidates checklist: identify the closed interval, find critical points, evaluate the function at endpoints and critical points, and compare all values to locate the extrema.
A continuous function $p$ on $-2,5$ has critical points $x=1,4$. If $p(-2)=0,p(1)=2,p(4)=6,p(5)=3$, where is the absolute maximum?
At $x=1$
At $x=5$
At $x=-2$
At $x=4$
At $x=-2$ or $x=5$ only
Explanation
This problem assesses the Candidates Test, which is used to find absolute extrema of a continuous function on a closed interval. To apply the Candidates Test, we evaluate the function at all critical points inside the interval and at the endpoints. Critical points are where the derivative is zero or undefined, potentially indicating local maxima or minima. Endpoints must be checked because the absolute extremum could occur there, even without a zero derivative. A tempting distractor might be choosing x=1, but p(1)=2 is less than p(4)=6, so it's not the maximum. Remember, the checklist for candidates is: list all critical points in the interval, include both endpoints, evaluate f at each, and compare the values to find the max or min.
A continuous function $g$ on $-6,-2$ has critical points $x=-5,-3$. If $g(-6)=2,g(-5)=1,g(-3)=0,g(-2)=3$, where is the absolute minimum?
At $x=-5$
At $x=-3$
At $x=-2$
At $x=-6$
At $x=-6$ or $x=-2$ only
Explanation
This problem assesses the Candidates Test, which is used to find absolute extrema of a continuous function on a closed interval. To apply the Candidates Test, we evaluate the function at all critical points inside the interval and at the endpoints. Critical points are where the derivative is zero or undefined, potentially indicating local maxima or minima. Endpoints must be checked because the absolute extremum could occur there, even without a zero derivative. A tempting distractor might be choosing x=-5, but g(-5)=1 is greater than g(-3)=0, so it's not the minimum. Remember, the checklist for candidates is: list all critical points in the interval, include both endpoints, evaluate f at each, and compare the values to find the max or min.
A continuous function $h$ on $0,5$ has critical points $x=1,4$. If $h(0)=2,h(1)=0,h(4)=3,h(5)=1$, where is the absolute maximum?
At $x=5$
At $x=0$ only
At $x=1$
At $x=0$
At $x=4$
Explanation
This problem assesses the Candidates Test, which is used to find absolute extrema of a continuous function on a closed interval. To apply the Candidates Test, we evaluate the function at all critical points inside the interval and at the endpoints. Critical points are where the derivative is zero or undefined, potentially indicating local maxima or minima. Endpoints must be checked because the absolute extremum could occur there, even without a zero derivative. A tempting distractor might be choosing x=1, but h(1)=0 is less than h(4)=3, so it's not the maximum. Remember, the checklist for candidates is: list all critical points in the interval, include both endpoints, evaluate f at each, and compare the values to find the max or min.
A continuous function $f$ on $2,8$ has critical points $x=3,7$. If $f(2)=5,f(3)=4,f(7)=6,f(8)=1$, where is the absolute minimum?
At $x=2$ or $x=8$ only
At $x=7$
At $x=2$
At $x=3$
At $x=8$
Explanation
This problem assesses the Candidates Test, which is used to find absolute extrema of a continuous function on a closed interval. To apply the Candidates Test, we evaluate the function at all critical points inside the interval and at the endpoints. Critical points are where the derivative is zero or undefined, potentially indicating local maxima or minima. Endpoints must be checked because the absolute extremum could occur there, even without a zero derivative. A tempting distractor might be choosing x=3, but f(3)=4 is greater than f(8)=1, so it's not the minimum. Remember, the checklist for candidates is: list all critical points in the interval, include both endpoints, evaluate f at each, and compare the values to find the max or min.
For continuous $v$ on $1,5$ with critical points $x=2,4$ and $v(1)=-2,v(2)=0,v(4)=-3,v(5)=-1$, where is the absolute maximum?
$x=2$
$x=5$
$x=1$
$x=1$ and $x=5$
$x=4$
Explanation
This problem demonstrates the Candidates Test for finding the absolute maximum on [1, 5]. The Candidates Test requires examining critical points (x = 2, 4) and endpoints (x = 1, 5) of continuous function v. With v(1) = -2, v(2) = 0, v(4) = -3, and v(5) = -1, we compare all four values to find the largest. The maximum value is 0, which occurs at x = 2, making this critical point the location of the absolute maximum. A common mistake is thinking the maximum must be at an endpoint or choosing x = 5 because it has the largest value among endpoints, but the Candidates Test requires comparing all candidates equally. Follow the systematic approach: list critical points and endpoints, evaluate the function at each, and identify the location with the maximum value.
A continuous function $g$ on $0,6$ has critical points $x=2,5$ and values $g(0)=1,g(2)=4,g(5)=0,g(6)=3$; where is the absolute minimum?
$x=6$
$x=2$
There is no absolute minimum on $[0,6]$
$x=0$
$x=5$
Explanation
This problem applies the Candidates Test with given function values to find the absolute minimum. The Candidates Test requires checking all critical points (x = 2, 5) and endpoints (x = 0, 6) for a continuous function on [0, 6]. We have g(0) = 1, g(2) = 4, g(5) = 0, and g(6) = 3, so we compare these four values to find the smallest. The minimum value is 0, which occurs at x = 5, making this the location of the absolute minimum. Students might incorrectly choose x = 0 thinking the endpoint with the second-smallest value is the answer, but the Candidates Test requires finding the actual minimum value among all candidates. Remember the Candidates Test checklist: identify all critical points, include both endpoints, evaluate the function at all candidates, and compare to find extrema.
A continuous function $h$ on $-4,0$ has critical points $x=-3,-1$. If $h(-4)=0,h(-3)=2,h(-1)=1,h(0)=3$, where is the absolute maximum?
At $x=0$
At $x=-4$ only
At $x=-1$
At $x=-3$
At $x=-4$
Explanation
This problem assesses the Candidates Test, which is used to find absolute extrema of a continuous function on a closed interval. To apply the Candidates Test, we evaluate the function at all critical points inside the interval and at the endpoints. Critical points are where the derivative is zero or undefined, potentially indicating local maxima or minima. Endpoints must be checked because the absolute extremum could occur there, even without a zero derivative. A tempting distractor might be choosing $x=-3$, but $h(-3)=2$ is less than $h(0)=3$, so it's not the maximum. Remember, the checklist for candidates is: list all critical points in the interval, include both endpoints, evaluate $f$ at each, and compare the values to find the max or min.