Question

Solve the equation: Sin2x - Sinx = 0

Answer 1

We know that sin2x=2sinxcosx 
(search the net for proof if you wish) 

So the original equation becomes

2sinxcosx-sinx=0
The two terms both have sinx that can be taken out to get: 

sinx(2cosx-1)=0 
This is true if sinx=0 or 2cosx-1=0 , rewritten: cosx=1/2

sinx=0 than x=2kπ
cosx=1/2 than x=π/3+2kπ
where k is an integer