" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2025 KUDO.TIPS - All rights reserved.
Verified answer
2 cos a cos b = cos (a + b) + cos (a - b)2 cos 37° cos 20°
= cos (37 + 10) + cos (37 - 20)
= cos 47° + cos 17°