Differentiate with respect to t.

y = a cos(t) + t^2 sin(t)

yo what is a

No clue. That is all im given

okay.

t^{2 }cos(t)+ 2t sin (t) - sin (t)

"a" just denotes some constant.....so

y = acos(t) + t^2sin (t)

y ' = - a sin(t) + 2t sin (t) + t^2 cos(t) =

(2t - a) sin (t) + t^2 cos (t)

Sorry for the late response but I understand now. I didn't even see the product rule between t^2 and sin(t).