Question 924299
<pre>
{{{2cos^2(theta) - sin(theta) = 1}}}

Replace {{{cos^2(theta)}}} by {{{1-sin^2(theta)}}}

{{{2(1^""-sin^2(theta)^"") - sin(theta) = 1}}}

{{{2-2sin^2(theta) - sin(theta) = 1}}}

{{{2-2sin^2(theta) - sin(theta) - 1=0}}}

{{{-2sin^2(theta) - sin(theta) + 1=0}}}

{{{2sin^2(theta) + sin(theta) - 1=0}}}

{{{(2sin(theta)^""-1)(sin(theta)^""+1)=0}}}

{{{2sin(theta)-1=0}}}; {{{sin(theta)+1=0}}}

{{{sin(theta)=1/2}}};  {{{sin(theta)=-1}}}

For {{{sin(theta)=1/2}}};

{{{theta=pi/6+2pi*k}}};  {{{theta=5pi/6+2pi*k}}}


For {{{sin(theta)=-1}}}

{{{theta=3pi/2+2pi*k}}}

Edwin</pre>