Question

Value of  2(cos4A -sin4A) ,if  cos2A - sin2A =1
​

Answer 1

Answer:

sinA+sin

2

=1

sinA=1−sin

2

A

sinA=cos

2

A

Now

cos

2

A+cos

2

A.cos

2

A

=sinA+sin

2

A

=1 ...(given)