Find all solutions to the equation.
7 sin2x - 14 sin x + 2 = -5
I've gotten part of this but am stuck.
7 sin^2(x)-14 sin(x)+2=-5
7 sin^2(x)-14 sin(x)=-7
sin^2(x)-14 sin(x)=-1

Question

Find all solutions to the equation.
7 sin2x - 14 sin x + 2 = -5
I've gotten part of this but am stuck.
7 sin^2(x)-14 sin(x)+2=-5
7 sin^2(x)-14 sin(x)=-7
sin^2(x)-14 sin(x)=-1

anonymous · Answer

Like in a normal quadratic equation, you can use the quadratic formula.  Just use sin(x) instead of x in it.

michele_laino · Answer

we have to use this substitution:
$$\sin x = t$$

anonymous · Answer

also, check the coefficient on your sin(x) term

anonymous · Answer

So would I factor from where it is at now

anonymous · Answer

Or factor at the beginning

anonymous · Answer

Yeah.  If you look at it like Michele_Laino said, it's like solving the equation

$$ t^2 -2t+1=0$$

Just when you find the solution, you resubstitute the sin(x)

anonymous · Answer

From where it's at now.

anonymous · Answer

Ok thanks so much guys.

anonymous · Answer

Welcome welcome ^_^