Find all solutions of the equation 2 cos x − 1 = 0 on 0 ≤ x < 2 π The answers are A and B, where A < B

Answer 1

2 cos x − 1 = 0

Simplify to get cos x = 1/2

for 0 ≤ x < 2 π

the potential solutions are x = π/3, 2π - π/3

For A < B,

A = π/3, B = 2π - π/3.