Question

Evaluate cos 48THETA
cos 42THETA − sin 48THETA
sin 42THETA

Answer 1

Answer:

Let theta be x ,

=cos 48x cos 42 x - sin 48x sin 42x

=cos 48x sin(90-42) - sin 48x cos(90-42)

=cos 48x sin 48x - sin 48x cos 48

=1*1

=1

*I hope it helps ; )*