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Related Rates Homework

So I have this problem that I have no idea what to do. I get the process of how to these problems but it's just that I don't exactly know which equation I derive in this one and what to plug in afterwards mainly because I have no idea what I'm finding in respect to time.

A particle is moving around the ellipse 4x^2+16y^2=64. At anytime [i]t[/i] , its x- and y- coordinate are given x([i]t[/i])=4cos[i]t[/i] and y([i]t[/i])=2sin[i]t[/i]. At what rate is the particle's distance to the point, (2,0) changing at any time [i]t[/i]? At what rate is the distance changing, when [i]t[/i]= pi/4 ?

September 23, 2012

6 Comments • Newest first

LowWillpower

[quote=Ickest]Oh God. Related Rates: THE WORST TOPIC IN AP CALC. [/quote]
Then AP calc was easier then my regular HS calculus?

Related rates was easy. Me & my friend read the chapter 5 minutes before class in the cafeteria (and because it was highschool, we were pretty high) and did like half the examples in the textbook in that 1.5 hour class.

Reply September 23, 2012
eyedrop

im in grade 11 and wat is dis o.0

Reply September 23, 2012
deraykhel

You should be the Mathematician here....
jk, but I have no idea, so have this free post that may or may not help bring out more help.

Reply September 23, 2012
supernoob

@Ickest: No topic in AP Calc is hard.* What I meant is, AP Calc is nothing compared to Calc III. I'm taking Calc III under the name Multivariable Calculus as a course in high school. Therefore, it's still technically an advanced placement course, just without the [AP] tag.

Reply September 23, 2012
supernoob

[quote=Ickest]Oh God. Related Rates: THE WORST TOPIC IN AP CALC. [/quote]

This isn't even that bad, and I'm not mathematically inclined. Delta-Epsilon, now THAT makes no sense.

Edit: Why are you on parametrics already? In any case.. the distance the particle is from the point at any time is sqrt((x(t) - 2)^2, (y(t) - 0)^2)

Just find dx/dt and dy/dt, differentiate the previous equation, and plug stuff back in. You should get an equation with "t" as a parameter.

Reply September 23, 2012 - edited
radkai

I don't learn this yet.

Reply September 23, 2012 - edited