If #2cosAcosB=cos(x)+cos(y)#, then #x+y=#??
1 Answer
Sep 16, 2016
2A
Explanation:
cos x + cos y = 2cos A.cos B (1)
Use trig identity:
Compare (1) and (2), we get:
2A
cos x + cos y = 2cos A.cos B (1)
Use trig identity:
Compare (1) and (2), we get: