Starting the AP calc thread.

Test Preparation AP Test Preparation
1

<p>Here are my answers. The teacher gave me back my sheet so I got all my answers now (well most of em)</p>

<li>a. I had about 37.913 or something. b. i had somewhere near 595 pi.</li>
</ol>

<p>c. I was not too sure. I did this.</p>

<p>Since they said semi circles I made my crossections equal to this
area = pi * d^2 / 8 (d = diamter.)</p>

<p>Then since it was perpinedicular to the x-axis I solved for y (i was not sure. Does this mean you use the y value or x value)?</p>

<p>Anyhow I did</p>

<p>area = pi * (20/(1+x^2) ^ 2 / 8 which was about 50-59 pi (i have no calc now so i cant check).</p>

<li><p>was easy. First one was about 8.4k (around)
b. was from (0, 1.617) U (3, 5.076)
c. at time = 3.</p></li>
<li><p>was hard.
a. 1 < r < 3 F(R) = -5
F(X) = F(G(X)) - 6
so 1 = F(G(R))</p></li>
</ol>

<p>I found all values of F(G(1 to 3) and once I did, I graphed it and it crosses the value of 1 at ONE point so I proved it</p>

<p>b. I took DY (F(G(X)) and did same thing.</p>

<p>c. Second fund. calc says that this one is simply F(G(3)) which was -1
d. they give x = 2. So we just find the inverse value (or y value and we get 3).</p>

<p>Now we need the slope. I used G`(X) value @ x = 3 to find it i think…

  1. a. 5PI / 4 (took deriv. Found crit points. Did first d. test and when I got a minus sign and then a plus, it was a minimum (since it was X(T)) the minimum would be the furthest left point). b. Ok this one was ANNOYING. I hated it.

EVENtually it worked out and I got a = 1/2 or -1/2

  1. I just used the value of (5, 30) m = 2. I put lesser than. Not really sure why..

b. Easy. Differentiate the equation and plug in.

c. Right hand sums. I forgot answer... but simple d. Less than because these right hand sums fall below the curve.

6.

a. F(X) = k/ 2 sq. x - 1 /x F`(X) = -k / 4 (X^1.5) + 1 / x^2 b. it has one at k = 3 c. Ok this one baffled me. I set the second d. equal to 0. Now i got this far.</p>

<p>k sq X = 0</p>

<p>I had no clue where to go so I used the value of x = 1 from the last problem… and got k = 4. Total guess.</p>

<p>So here you go. Post what you got!</p>

2

<p>for 2b). I believe it was (0,1.617)U(5.076,7), test a point</p>

3

<p>wow i sure screwed this up</p>

4

<p>Hey hey. I never said I was right 100% on these. I want to see what you guys have.</p>

<p>And for 2b... what do you mean? Graph 2 (the decreasing one) was ALWAYS above graph 1 from my two intervals and therefore rate increase would be decreasing.. if you go from (5.076, 7) rate increase is greater than rate decrease..</p>

5

<p>I had a different test since I took mine at a DoDDs school in Europe.</p>

6

<p>2a was 3000 something bc it said how much entered and 5000 was already in there</p>

7

<p>You dont subtract out the intital 5000. ITs just the integral of the rate of entering from 0 to 8.</p>

8

<p>gaaaaaaaaaaaaaah
just realized that</p>

<p>was the Q how much has entered or is in it?</p>

9

<p>How much enters it.</p>

10

<p><a href="http://apcentral.collegeboard.com/apc/public/repository/ap07_calculus_ab_frq.pdf%5B/url%5D"&gt;http://apcentral.collegeboard.com/apc/public/repository/ap07_calculus_ab_frq.pdf&lt;/a&gt;&lt;/p>

<h1>1 is ambiguous and needs to be removed unless I got it right.</h1>

11

<p>Rofl I never even saw the 5000 part. But it does say ENTERING. If it says entering + leaving it would be 3000 some (because if you do the integrals you get about -1200). See when I took the test I got -1200 or so. i was like... how are -1200 gallons leaving... when there is none to begin (never saw that 5000). Now its all cleared up. I think it is 8k something.</p>

12

<p>number 3 i just used a paragraph to explain... not very mathematical. would it work if i kept giving the ranges of possibel answers once you plug in one number and continue and at the end, the number they gave as in that range?</p>

13

<p>Hey guys check out form B. It's wayy easier.</p>

14

<p>I think it would as long as you proved it. But why does number 1 have to be removed...? can you explain?</p>

15

<p>I screrwed up so bad. I had no clue what to do on the water tank problem. How much trouble am I in if I shaded the wrong region for revolution? I am soo mad at myself. I let my nervousness get the best of me in the FRQs!! I want to cry now! I screwed like all of them up! I'm counting on the mltiple choice!!</p>

16

<p>i am pretty sure if you carry a mistake through, you don't get points off for every time you do it</p>

17

<p>I didn't see the G graph stuff!! GRRRR</p>

18

<p>If you look at the graph (<a href="http://img241.imageshack.us/img241/153/number1gj6.jpg%5B/url%5D"&gt;http://img241.imageshack.us/img241/153/number1gj6.jpg&lt;/a&gt;), you will see that when you shade the area above the y=20/(1+x^2) and below the y=2 graph...you do not get a definite integral.</p>

19

<p>It is a definite integral.
Look above the window.</p>

20

<p>I feel like such an idiot, I misread the problem and took the integral BELOW y=2 and the function, but still bounded by the X-axis. It was much more difficult, taking the limits to infinity after integrating, and it screwed me up for the rest of it.</p>