Question

if A+B+C = 180 ,sin A- sinB + sinC =
4 sin A/2 *cosB/2 * sinC/2
Prove.
pls tell me how to do this..

Answer 1

http://www.wolframalpha.com/input/?i=sin%28A%29+-+sin%28B%29+%2B+sin%28C%29+%3D+4*%28sin%28A%29%2F2+*cos%28B%29%2F2+*+sin%28C%29%2F2%29

Answer 2

thanks a lot...it really helped... :)