Question

How do you calculate the antiderivative of `sin(2x)/cos(x) dx`?

Answer 1

The integral/antiderivative you require is

`I = intsin(2x)/cos(x)dx`

The easiest way to solve it is to use trigonometric identities and expand the numerator, like this

`sin(2x) = 2sinxcosx`

This transforms the integral in this way

`I = int2sinxcosx/cosxdx`
`=> I = 2intsinxdx`
`=> I = -2cosx + C`