Question

How do you find the antiderivative of `cos(3x)`?

Answer 1

`" "intcos3xdx=1/3sin3x+C`

Explanation:

we want`" "intcos3xdx`

we know

`d/(dx)(sin3x)=3cos3x" "`using the chain rule.

so`" "intcos3xdx=1/3sin3x+C`