# Solving for A in Sin(A+b)

1. Sep 23, 2010

### joemama69

1. The problem statement, all variables and given/known data

given this formula, i have to solve for A

n=sin[(A+B)/2]/sin(B/2)

2. Relevant equations

3. The attempt at a solution

Heres how far I got

2nsin(B/2) = sin(A+B) i know this can expand out to
=sinAcosB + cosAsinB but this isnt much help. Anyone got a suggestion

2. Sep 23, 2010

### Susanne217

Made me think of the interweb

$$sin(\frac{B}{2}) = sin(\frac{B}{2}) = \frac{1-cos(B)}{2}$$

Last edited: Sep 23, 2010