I would start by using the trig identity
Using that, so that the equation is the same as . If you let y= sin(x), that is . Can you solve that quadratic equation for y and then solve for x?
Thanks for answering
I solved quadratic equation 4u^2+4u-3=0 (sinx=u)
u2=-1.5 (dont satisfy)
so sinx=1/2 but i need to write two separate answers, what x1 and x2 are, but i get this
x=(-1)^n * Pi/6 + 2Pin
how to write two answers from that one, which i learned? please help