Find all possible solutions in the range 0°≤ x ≤ 180° of the following equations:

Question

(a) cos x = sqrt(2) / 2

(b) tan x = sqrt(3) / 3

(c) sin x = sin60°

(d) cos x = -1/2

(e) sin x = -1/2

Answer 1

find the reference angle in QI.
only sin x is positive in QII.

For example,
cos x = √2/2
x = 45°
Since cos x < 0 in QII, that is the only solution.

Work the others in like wise.