# Homework Help: Parametrics help

1. Nov 12, 2007

### saywhaaaat

1. The problem statement, all variables and given/known data
A particle moves in the xy-plane so that its position at any time t, 0 less than or equal to t, less than or equal to pi, is given by x(t) = ((t squared)/2))-ln(1+t) and y(t) = 3sint

a. sketch
b. At what time t, 0 less than or equal to t, less than or equal to pi, does x(t) attain its minimum value? What is the position (x(t), y(t)) of the particle at this time?
c. At what time t, 0 less than or equal to t, less than or equal to pi, is the particle on the y-axis? Find the speed and the acceleration vector of the particle at this time.

2. Relevant equations

3. The attempt at a solution

b. t=0, pi

c. set x(t) function to 0?

2. Nov 12, 2007

### EnumaElish

c. Yes.
b. Can you describe how you got this answer?

3. Nov 12, 2007

### ace123

Well it seems like you know what to do for the problem but you didn't show us any work for how you got the answer. So we can't help much