Question

cos 3 x = 4cos ^3 x - 3cos x, x = 30

Answer 1

Step-by-step explanation:

L.H.S

=>cos 3*30°

=>cos 90°

=>0

R.H.S

=>4cos³ x- 3cos x

4cos³ 30°- 3cos 30°

=>4×(√3/2)³-3×√3/2

=>4*3√3 -3√3

8 2

=>12√3 -4(3√3)

8

=>12√3-12√3

8

=>0/8=0

hope it helps ☺️