Question

I really need help with number 9.

Answer 1

Answer:

2/4 = 1/2

Step-by-step explanation:

Firstly expand cos(x - 30)....which is..

[cos x.cos 30 + sin x.sin 30]

If sin x = -1/2...then cos x = square root of 3/2

Then substitute the values into the expansion above....which...,

[(square root of 3/2)(square root of 3/2) + (-1/2)(1/2) ]

; 3/4 - 1/4 = 2/4

;Ans = 2/4 = 1/2