# $\sin{(A+B)}$ formula

## Formula

$\sin{(A+B)}$ $\,=\,$ $\sin{A}\cos{B}$ $+$ $\cos{A}\sin{B}$

### Introduction

$A$ and $B$ are two angles and the sum of them is written as $A+B$. Sine of sum of angles $A$ and $B$ is written as $\sin{(A+B)}$ in trigonometric mathematics. The $\sin{(A+B)}$ identity is used as a trigonometric formula and it is mainly used to expand in terms of sine and cosines of angles $A$ and $B$.

#### Proof

Learn how to derive sin of sum of angles in geometrical method.