Question

Solve each equation for θ with 0 ≤ θ <2 π.

sin²θ+3sinθ=0

Answer 1

Explanation:

At first, we should factorize the equation:

sin²θ+3sinθ=0

sinθ(sinθ+3)=0

Either sinθ=0 or sinθ+3=0:

If sinθ=0, then θ=0 or θ=180

If sinθ+3=0, then sinθ=-3. This is not possible, because the maximum value of sinθ is 1.

Therefore, the only solution is θ=0 or θ=180°.