Answer:
t ∈ {0, 0.252680, 2.888912, 3.141593}
Step-by-step explanation:
Simplify and factor.
4sin(t)^2 -sin(t) = 0 . . . . use tan=sin/cos, subtract 6sin(t), divide by 6
sin(t)(4sin(t) -1) = 0 . . . . factor
Solutions make the factors zero.
sin(t) = 0 ⇒ t = 0, π
4sin(t) -1 = 0 ⇒ t = arcsin(1/4), π-arcsin(1/4) ≈ 0.252680, 2.888912
t ∈ {0, 0.252680, 2.888912, 3.141593}