Question

lved Examples
Find the value of cos 42° – sin 48°.
We have​

Answer 1

Answer:

Step-by-step explanation:

Cos42° - Sin48°

Sin48° = Sin(90° - 42°)

           = Cos42°   (∵ Sin(90 - θ) = Cosθ)

Now Cos42° - Sin48° = Cos42° - Cos42° = 0.

 

Answer 2

Answer:

since. sin (90-A) = cos A

therefor sin 48 = cos 42

thus cos 42 - sin 48 =0