Question

Find all solutions to the equation. 7 sin2x - 14 sin x + 2 = -5

Answer 1

i think u have to substitute sin x with y

7y^2 - 14y + 2 = -5
add 5 to both sides

7y^2 - 14y + 7 = 0
divide everything by 7


y^2 - 2 y + 1 = 0
(y - 1)(y - 1) = 0
so the solution is y =1


y = sin (x) = 1
when is sin(x) = 1?

Answer 2

Surdawl did exactly what I was about to type!

Answer 3

so there is only one solution?

Answer 4

Yes?

Answer 5

seems right to me.

Answer 6

thanks so much!