Question

can anyone explain related rates to me lol ):

Answer 1

yes related rates are my favourite right now =)!!

Answer 2

The best way to understand them is through examples like a lot of examples because there are different methods to solving different problems although there are basic similarities you need to look for slightly different things depending on the problem.

Answer 3

OMG PRAISE THE LORD they are the one thing killing me right now I am so afraid of getting one tomorrow as a free response.

Answer 4

ok so if i send you an old free response question that has a related rates problem can we go through it together?

Answer 5

for sure =)

Answer 6

http://apcentral.collegeboard.com/apc/public/repository/ap08_calculus_ab_frq.pdf

Answer 7

it is number 3, I was doing it today in class, and idk the concept still isnt sinking in my head.

Answer 8

alright one sec I'll take a look

Answer 9

okay so far part a looks not to bad the first thing I always do is set my rates of change up with there variables and set my constants or the things for the given time they want to know do you want to do that now?

Answer 10

ok :) so on my paper i wrote the given information down ( r=100, h = 0.5 dr/dt= 2.5/min and v= pir^2h and i found the derivative of that. which is 2*pi*r . it's like after I found the derivative, I know i have to start plugging in some of the data given, but I am so lost o.o

Answer 11

oh wait see that's the problem you needed to do implicit differentiation remember you also dv/dt so you can solve this using implicit differentiation.

Answer 12

any time you see a related rates problem you need to find an equation that relates the rates and then possible get rid of a variable or something and then you use implicit differentiation to solve for whatever rate you don't have you know what I mean?

Answer 13

In this case you did not need to get rid of a variable which is nice because that is usually the hardest part.

Answer 14

O.o I overlooked something I just figured out -sigh-

Answer 15

=) making mistakes, and overlooking things is how we learn.

Answer 16

lol it freaks me out, I shouldnt be making these kinds of mistakes the night before my AP EXAM. I am going through an emotional breakdown right now lol.

Answer 17

don't worry you will be fine just keep going I spent hours helping someone through related rates problems the other night and think of it like this you are practicing both implicit differentiation and related rates problems so it will help you in two ways =)

Answer 18

once you do implicit differentiation to v=pir^2h you will be able to plug in all the values you have do you want to show me what you have? If you want I know of some common related rates problems. They get easier once you work through them. The ones where you have to cancel out variables will be a little bit harder buts once you do a few you will be able to pick out general patterns and you will solve them real fast tomorrow.

Answer 19

okay well incase you come back I don't know if you have the answer to this question somewhere but you should end up with v^t = 2pirr^th + pir^2h^t then you do algebra from there to isolate h^t and plug in your variables and get 0.039cm/min I think that's right.

Answer 20

related rates:
Calculus + geometry formula + implicit differentiation + you will see if on the AP exam. AP loves to put it on FRQ