Question

How do I solve 4cos^2 x -1=0

Answer 1

pi/3? 2pi/3?

Explanation:

Answer 2

`(cosx)^(2) = 1/4` <=> cosx = +1/2 or cosx = -1/2;
cosx = +1/2 => x = +π/3 + 2kπ, where k is an integer or x = -π/3 + 2kπ, where k is an integer;
cosx = -1/2 => x = +2π/3 + 2kπ, where k is an integer or x = -2π/3 + 2kπ, where k is an integer;