Question 769960
Do you mean this:  {{{ 2(sin t)^2 - 3 sin t + 1 = 0 }}} ?


Quadratic equation in sin(t).
{{{sin(t)=(3+-sqrt(9-4*2))/4}}}
{{{sin(t)={3+-sqrt(1))/4}}}
{{{sin(t)=(3+-1)/4}}}
{{{sin(t)=1/2}}} or {{{sin(t)=1}}}


{{{t=pi/3}}} or {{{t=2*pi/3}}} or {{{t=pi}}}
Through referring to the unit-circle.