Question

if a=60° and b=30°, find the value of (sin a cos b + cos a sin b) ^2 - (cos a cos b - sin a sin b) ^2

Answer 1

Answer:

1

Step-by-step explanation:

sina =cosb sinb=cosa

as 30= 90-60

sin30=cos60 & cos30=sin60

(sinacob+cosasinb)^2-(cosacosb-sinasinb)^2

=(sin^2a +cos^2a)^2 -(sinbsina-sinasinb)^2

=1^2 - 0

=1

Answer 2

= [sin(a+b)]² - [cos(a+b)]²
= a=60° and b=30°
= sin²90° - cos²90
= 1 - 0
= (1)