Question

help me in this
evaluate cos48°-sin42° by steps

Answer 1

We know that cos thita = sin(90-thita)

now look at the ques.

Cos 48 degree - sin 42 degree

= cos(90deg. -42deg.) - sin42 deg.

=  sin42 deg. - sin 42 deg.

=  0

Answer 2

Cos48-sin42= sin(90-48)-sin42. (Cos(90-theta)=sin theta
=sin42-sin42
=0