Answer: see proof below
<u>Step-by-step explanation:</u>
Given: cos 330 = 
Use the Double-Angle Identity: cos 2A = 2 cos² A - 1

Proof LHS → RHS:
LHS cos 165
Double-Angle: cos (2 · 165) = 2 cos² 165 - 1
⇒ cos 330 = 2 cos² 165 - 1
⇒ 2 cos² 165 = cos 330 + 1
Given: 

Divide by 2: 

Square root: 
Scratchwork: 

Since cos 165 is in the 2nd Quadrant, the sign is NEGATIVE

LHS = RHS 
The equation has three factors and equals zero
One of the factors must be zero.
Either 3x = 0 which means x = 0
or x - 4 = 0 which means x = 4
or 3x + 5 = 0 which means 3x = -5 so x = -5/3
The answer is C
E cannot be correct in this question as you are asked to “solve” and not just pick a correct option
Answer:
Hope the picture will help you
Answer:
(4,2 1/2)
Step-by-step explanation: