Question

How do you integrate `sin(3x) dx`?

Answer 1

The answer is`-(cos3x)/3+C`

Explanation:

The integral of `sintheta` is `-costheta`
You can use the substitution, `u=3x` the `du=3dx`
`intsin3xdx=int(sinudu)/3=-cosu/3=-(cos3x)/3+C`