Question

solve: 5 sin^2(x) = cos x 0< x < 2

Answer 1

remember sin^2x+cos^2x=1
so sin^2x=1-cos^2x
so we have
5(1-cos^2x)=cosx
5-5cos^2x=cosx
-5cos^2x-cosx+5=0
5cos^2x+cosx-5=0
this is a quadratic equation
let u=cosx
u^2=cos^2x
so we have
5u^2+u-5=0
solve this for u
and then don't foget u=cosx and then you can solve for x

Answer 2

thank you