Question

4 sin^2 + 2 sin x - 3

Answer 1

Answer:

Let sin x=t,

f(t)=t^2+2t-3=0

since a+b+c=0one real root is t=1 and the other:t=c/a=-3

slove:-t=sinx=1=sin=pi/2-x =pi/2

the solution t=-3is rejected