Question

Suppose an object moves in an elliptical orbit parametrized by

x = 2 cos t and y = 7 sin t, where t ≥ 0.

Determine the value of the velocity at the indicated times:
v(pi/4)
v(pi/2)

Answer 1

for v(pi/4) I got 2 (which was wrong) by taking the sqrt((-2sin(pi/4))^2) + (2cos(pi/4))^2)).. ifyou have any idea where I went wrong, I would appreciate the help!!

Answer 2

Velocity is a vector.

Answer 3

I don't think you need to find the magnitude.

Answer 4

\[
v_x=-2\sin t\\
v_y=7\cos t
\]

Answer 5

now to find magn. take sqrt of ((-2sint)^2+(7cost)^2)

Answer 6

subst. t =pi/4 or pi/2