Proceed from the RHS,
2+ (2sinAsinB)sinC
= 2+ {cos(A-B)-cos(A+B)}sinC
=2+ {cos(A-B) - cos (Ï€/2 - C)} sinC
=2+ cos(A-B)sinC - sin2C
Now in cos(A-B)sinC again apply the formula for sinAcosB and proceed..
- Himanshu Giria hmmm./..thanks...
Upvote·0· Reply ·2014-03-06 01:05:33