Question

Find all solutions in the interval [0, 2π).
sin^2x + sin x = 0

Answer 1

Rewrite the problem as (sin x)^2 + sin x = 0 and solve like a quadratic equation using the zero-product rule. Does that help?

Answer 2

could you show me how to do that please?

Answer 3

No problem.

Answer 4

Factor out sin x so that the equation looks like this: sin x (sin x + 1) = 0. Solve for sin x AND sin x +1. That'll look something like this:

Answer 5

sin x = 0 at 0 and pi. sin x = -1 at 3pi/2. So your answers to the problem should be 0/2pi, pi, and 3pi/2