Question

(c ) If A =60° and B= 30°, find the value of
(sin A.Cos B + Cos A.Sin B)2 +(Cos A.cos B- sinA. Sin B )2?​

Answer 1

Explanation:

(sinA.cosB+cosA.sinB)2+(cosA.cosB-sinA.sinB)2

(sin(A+B))2+(cos(A+B))2............1

(Sin(a+b)=sinacosb+cosasinb)

(cos(a+b)=cosacosb- sinasinb)

substitute A=60 andB=30 in above

equation

(sin(60+30))2+(cos(60+30))2

(sin90)2+ (cos(90))2.

( sin90=1 ,cos90=0. )

(1)2+(0)2

2+0

=. 2