Question

$\cos(\pi \div 4 - x) \cos(\pi \div 4 - y) - \sin(\pi \div 4 - x) \sin(\pi \div 4 - y) = \sin((x + y)$
proove this ​

Answer 1

Answer:

See the above solution..

HOPE IT HELPS YOU DEAR.......

WITH LOVE, ARCHANA:-)