Question

what is the integral of 3sin(3t)?

Answer 1

3(cos3t)/3
cos3t

Answer 2

sorry -cos3t

Answer 3

intergral of sin3t is (-cos3t)/3

Answer 4

Possible intermediate steps:
integral 3 sin(3 t) dt
Factor out constants:
= 3 integral sin(3 t) dt
For the integrand sin(3 t), substitute u = 3 t and du = 3 dt:
= integral sin(u) du
The integral of sin(u) is -cos(u):
= -cos(u)+constant
Substitute back for u = 3 t:
= -cos(3 t)+constant