Question

How to solve this ?

Answer 1

First, we need to know that `sin(2x)=2sin(x)cos(x)`

`sin(2x)-sin(x)=0`
`2sin(x)cos(x)-sin(x)=0`
`(sinx)(2cosx-1)=0`

we have `sinx=0 or cosx=1/2`

When `sinx=0`, `x=0 or x=pi`
When `cosx=1/2`, `x=pi/3 or x=(5pi)/3`

Therefore, the answer is not only `0 and pi`, but also include `pi/3 and (5pi)/3`.

Here is the answer :) Hope it can help you.