Question

Show that:

(sin 2x + sin x) / (2 cos x +1) = sin x

For some reason the method of multiplying with the denominator is not valid because "The solution is based on the equality that we were trying to prove"

How would you solve this?

Answer 1

You need to use the formula for sin 2x, the rest pretty much takes care of itself on its own.

Answer 2

I see, thank you!