Solve the following equation: `\ 4sin^2theta-8costheta+1=0`

Explanation

Given,`4sin^2theta-8costheta+1=0`

=`4(1-cos)^2theta-8costheta+1=0`

=`-4cos^2theta-8costheta+5=0`

=`-4cos^2theta-10costheta+2costheta+5=0`

=`(-2costheta+1)(2costheta+5)=0`

=`costheta=1/2 or -5/2`

or `theta=60^0`