Working through Calc AB Free-Response Questions.

Test Preparation AP Mathematics & Computer Science
1

<p>A few questions here and there, I will list one for now:</p>

<p>Question 5.a)
<a href="http://apcentral.collegeboard.com/apc/members/repository/sg_calculus_ab_99.pdf%5B/url%5D"&gt;http://apcentral.collegeboard.com/apc/members/repository/sg_calculus_ab_99.pdf&lt;/a>
If it's an area, and is clearly above the x-axis, why is it listed as a negative area? [This is for g(-2)].</p>

<p>Is it because the integrand is negative? I mean, it just doesn't seem right to me as the graph is right there.</p>

2

<p>The reason is because g(-2) gives you the integral from 1 to -2. Whenever the bottom “integrand” is greater than the top “integrand,” you have to flip the integrands and multiply the entire integral by a negative sign.</p>

3

<p>Hmm, okay thanks!</p>

<p>Another:
<a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;
4.a) Shouldn’t it be 16/3. . . ?</p>

4

<p>The integral of sqrt(t+1) from 0 to 3 is (2/3)(3+1)^(3/2)-(2/3)(0+1)^(3/2) so that would be 16/3 - 2/3 which would be 14/3</p>

5

<p>Man, I didn’t realize that subbing in 0 would give a non-zero answer and thus would need to be subtracted.
Thanks!</p>