How Do You Isolate A in the Equation n=sin[(A+B)/2]/sin(B/2)?

[joemama69]

Homework Statement

given this formula, i have to solve for A

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

Homework Equations

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 isn't much help. Anyone got a suggestion

 

[Susanne217]

Homework Statement

given this formula, i have to solve for A

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

Homework Equations

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 isn't much help. Anyone got a suggestion

Made me think of the interweb

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