Question

Prove that Sin(π/4+x)sin(π/4-x)=1/2cos2x

Answer 1

Answer:

Step-by-step explanation:

Sin(π/4+x)sin(π/4-x)

=1/2(2Sin(π/4+x)sin(π/4-x))

=1/2*[cos(π/4-x-π/4-x)/2+cos(π/4-x+π/4+x)

=1/2[cos(-2x)+cos(π/4+π/4)]

=1/2(cos2x+0]

=1/2(cos2x

Answer 2

Step-by-step explanation:

answer in image given above