Question

(1) If 0 < A < 90 and cos A = sin 60 cos 30 - cos 60 sin 30, then A = ….

(a) 30 (b) 45 (c) 60 (d) 90​

Answer 1

Answer:

a) is wright answer

Step-by-step explanation:

sin60°=√3/2.

cos30°=√3/2

sin30°=1/2

cos60°=1/2

cosA=sin60°cos30°-cos60°sin30°

cosA=√3/2X√3/2-1/2X1/2

cosA=3/4-1/4

cosA=2/4

cosA=1/2

cosA=cos30°. ( because 1/2 is equal to cos30°)

A=30°