Question 958073
{{{sin(theta)=cos(2*theta)}}}
{{{sin(theta)=1-2sin^2(theta)}}}
Let {{{u=sin(theta)}}},
{{{u=1-2u^2}}}
{{{2u^2+u-1=0}}}
{{{(u+1)(2u-1)=0}}}
Two solutions:
{{{u+1=0}}}
{{{u=-1}}}
{{{sin(theta)=-1}}}
{{{theta=270}}}
and
{{{2u-1=0}}}
{{{2u=1}}}
{{{u=1/2}}}
{{{sin(theta)=1/2}}}
{{{theta=30}}} and {{{theta=150}}}