Related Rates

Test Preparation AP Test Preparation
1

<p>Hi,</p>

<p>Are formulas for area, volume, surface area, etc. of cones, cylinder, etc. provided on the Exam, or do you need to just memorize all of them?</p>

<p>For me, knowing and deciding what formula(s) to use is the hardest part in solving related rates problem.</p>

<p>While solving related rates problems for practice, I found that one of the most common formulas required is the volume of a cone, which is (3/4)(pie)r^2, but what other formulas are most likely to be needed?</p>

<p>If the Exam doesn't provide any of these formulas, then what formulas would be good to memorize before the Exam?</p>

<p>Thanks.</p>

2

<p>I would like to know the answer too lol, but I have a question to add on to this.</p>

<p>If you know other formulas, like those in physics, that can be applied to a problem, can you just go ahead and use them to solve problems without deriving them using calc?</p>

3

<p>Isn't the volume of a cone (1/3)pi*r^2?</p>

<p>My teacher told my class that we have to memorize them, but I'm not sure. Can someone that's taken the exam before verify?</p>

4

<p>The volume of a cone is 1/3<em>h</em>pi*r^2...</p>

<p>I'm pretty sure they don't provide them, but you really shouldn't need it, anyway.</p>

5

<p>
[quote]
The volume of a cone is 1/3<em>h</em>pi*r^2...

[/quote]

Sorry, I mixed that up with the volume of a circle, (4/3)(pi)(r^3). :o</p>

<p>
[quote]
I'm pretty sure they don't provide them, but you really shouldn't need it, anyway.

[/quote]

How should you not need it? Identifying and taking derivative of certain geometric formula is the first step in solving related rates problem. You really can't solve related rates problems if you don't know which geometric formula to start off with, right? Not knowing them will cost you marks.</p>

6

<p>You need to know the volume of a rectangular or triangular prism and cylinder. Anything else will be given.</p>

7

<p>You should know the formulas for areas and volumes of geometric shapes (circle, sphere, trapezoid, cone, pyramid, etc) by heart, that's basic stuff. I don't think they usually put anything nasty on the test but if they do they'll give you a formula.</p>

8

<p>um, sphere?</p>

9

<p>Related Rates is one of the few topics I'm not confident with. How many related rates questions and percent distribution can you expect on the actual exam?</p>

10

<p>Bump..... :)</p>

11

<p>Oh, by "you shouldn't need it" I mean that you learned that in geometry, and it's really just... intuitive.</p>

12

<p>does anyone know about the physics thing? because some probs are easier to solve just usong physics formulas that are already memorized rather than using the calc behind it...can we use the formulas or do we have to show where they came from(assuming its a free response of course)</p>

13

<p>I don't really think you can solve the AP Calc problems with Physics formulas. You have to go through the related rates process. I took the AB test last year and related rates wasn't a big part of the test at all.</p>

14

<p>Just going through old BC exams my teacher gave us, I've only found one multiple choice (though not that many have been released, he gave us 3) and there hasn't been one in the section II since '98. </p>

<p>Hope that trend continues! I'm not a big fan of related rates :(</p>

15

<p>Doodle: Do you know if that's the same for recent (2004, 2005, 2006) tests?</p>

16

<p>maximum of 2 questions on related rates in the multiple choice section. in the free response, they might have a whole problem on related rates. be familiar with them</p>

17

<p>If the FR section tests you a related rates question, it won't be terribly difficult, right?</p>

18

<p>naw it'll just make sure you know to get the right volume formula, differentiate it, plug in the rates, and solve</p>

19

<p>Tccc061990: That's relieving. Thanks for the reply. :)</p>

20

<p>hopefully it won't be as hard as the questions about related rates in the barrons book</p>