Posted by Catherine on Thursday, April 14, 2011 at 10:27pm.
A particle moves with its position given by x=cos(2t) and y=sin(t), where positions are given in feet from the origin and time t is in seconds.
A)Find the speed of the particle.
Speed = ____________
(include units)
B)Find the first positive time when the particle comes to a stop.
t=_____
(include units)
C)If n is any odd integer, write a formula (in terms of n) for all positive times t at which the particle comes to a stop.
t=______
(include units)
For the first one I got sqrt((2sin(2t))^2+(cost(t))^2) ft/s, which is wrong, and I don't know why....
I don't know ho to calculate the second and third part... please someone help...

Calculus (urgent!!)  Catherine, Thursday, April 14, 2011 at 11:00pm
Ok..I found the problem with my first part, I accidentally typed cost(t)^2... Ok I'm still stucked with the last two parts, I don't know what to do with them....