Question

Cos12degrees-sin78degrees

Answer 1

Cos 12°-sin78°
cos12°-cos(90-78)°
cos12°-cos12°=0

Answer 2

Hey

Here is your answer,

Cos 12° - sin 78°
= Cos (90-78)° - sin78°
= Sin 78° - sin 78°
=0

Hope it helps you!