" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2025 KUDO.TIPS - All rights reserved.
cos b=5/13 sin b=12/13
a.sin(a+b)=sinacosb+cosasinb
=4/5 5/13 + 3/5 12/13
=(20+36)/65 =56/65
b.cos(a-b)=cosacosb+sinasinb
=3/5 5/13 + 4/5 12/13=(15+48)/65 = 63/65