Question

sin^2(2x)-4sin2x-1=0
Not too sure which way I should go about this...

Answer 1

Try this http://openstudy.com/study#/updates/51598dbbe4b0507ceba254df

I answered this question today if i had to say its almost the exact same.

Answer 2

So...
(sin2x-2)=sqrt5
sin2x=2+sqrt5 or sin2x = 2-sqrt5

Answer 3

Would I now take the inverse of sin(2+sqrt5):
2x= sin^-1(2+sqrt5) ?..

Answer 4

yes

Answer 5

So...
2x=sin^-1(2-sqrt5)+2πk
x=((sin^-1(2-sqrt5)+πk)/2)

Answer 6

Great!

Answer 7

Though for some reason I only got one answer out of four. The actuall answers are 96.8, 173.2, 276.8, 353.2 (degrees) I got 173.2