Mark M. answered 05/21/21
Tutor
4.9
(954)
Retired Math prof with teaching and tutoring experience in trig.
tanθ - 2sinθ = 0
sinθ/cosθ - 2sinθ = 0
[sinθ - 2sinθcosθ] / cosθ = 0
sinθ(1 - 2cosθ) = 0
sinθ = 0 or cosθ = 1/2
sinθ = 0 when θ = kπ
cosθ = 1/2 when θ = π/3 + 2kπ or 5π/3 + 2kπ, k = 0, 1, -1, 2, -2, ...