# How do you prove: 2sinx = cosx?

##### 1 Answer
Mar 9, 2018

This can not be proven since it is not (in general) true.

#### Explanation:

As an obvious counter example:
If $x = 0$
then $\sin \left(x\right) = 0$ and $\cos \left(x\right) = 1$
and obviously $2 \cdot \sin \left(x\right) \ne \cos \left(x\right)$

Perhaps (?) you wanted to solve for $x$ given this equation.