## anonymous 3 years ago The equation of motion is $$\ s=2costy+3sint, t\le0$$. Find velocity/acceleration at time t. I took the derivative to find the velocity, but got 0...?

1. anonymous

is that 2cos(ty) ?

2. anonymous

Good catch! That's supposed to be a t only.

3. anonymous

so $s=2\cos(y) + 3\sin(t) , t \le0$ ?

4. anonymous

Oops cos(t)

5. anonymous

Well the velocity at time t is just the derivative. Can you differentiate that?

6. anonymous

@Dido525 I tried, but I got 0, which doesn't seem correct.

7. anonymous

Lets see:|dw:1351660147750:dw|

8. zepdrix

Oh that was a 2? :P sorry..

9. anonymous

@zepdrix yup

10. anonymous

11. anonymous

Would I add the derivates of each here? What happens to the constants?

12. anonymous

I just did the derivative for you O_o .

13. anonymous

I suppose I was confused by the constants...

14. anonymous

Ohh. If you have constants out in from you take out the constant, take the derivative of the function and multiply the constant back in.

15. anonymous

Ohh.Okay. I was getting the product rule confused with the addition one. So for the acceleration, I take the derivative of the derivative?

16. anonymous

Yep!

17. anonymous

Okay!! Thanks so much!!!

18. anonymous

Welcome :) .