Question

If cos (A + B) = 0, then sin (A - B) can be reduced to​

Answer 1

=> cos (A + B) = 0

=> cos (A + B) = cos 90°

=> (A + B) = 90

=> A = 90 - B

= sin (A - B)

= sin (90 - B - B)

= sin (90 - 2B)

= cos 2B