Question

Evaluate:

cos 48°- sin 42°

Answer 1

We know that, cos (90° − θ) = sin θ. 

So, 

cos 48° – sin 42°

= cos (90° − 42°) – sin 42°

= sin 42° – sin 42°

= 0 

Thus the value of cos 48° – sin 42° is 0.