**A multiple angle is an angle which is written as a multiple of single function**.

** **

__Example for multiple angles__

__Multiple angle formulas:__

1.

2.

3.

**Question1 :**

Solve

*Solution*

Consider the equation

Use the multiple formulae as follow:

Written as follows:

Set the factors equal to zero as follows:

Therefore, the solution is:

The general solution foris:

**Question 2:**

Check the identity

*Solution *

Use the multiple formulae as follows:

Hence the identity is proved.