Question

Solve: 2sin^2x - sinx = 10 0 15 years ago

Answer 1

Let u=sinx. Substitute then solve it like a normal quadratic equation. Then substitute the sinx back to solve for answers in terms of x.

Answer 2

but then what do I do with the 2 at the beginning? divide it?

Answer 3

You have this:
2(sinx)^2-sinx=10.
If you say u=sinx, then
2u^2-u=10
This is a normal quadratic equation.