Question

Prove that
cos 30°. cos 60%-sin 30° - sin 60 =0​

Answer 1

The correct answer is not 0, it is -1/2 . Please see the explanation.

Step-by-step explanation:

cos 30°. cos 60° - sin 30° - sin 60°

= √3/2 * 1/2 - 1/2 -√3/2

= √3/4-2(1+√3)/4

= (√3-2-√3)/4

= -1/2