Question 868068
Let {{{u=sin(theta)}}}
{{{2u^2-u=1}}}
{{{2u^2-u-1=0}}}
{{{(u-1)(2u+1)=0}}}
Two "u" solutions:
{{{u-1=0}}}
{{{u=1}}}
{{{sin(theta)=1}}}
{{{theta=90}}}
and
{{{2u+1=0}}}
{{{2u=-1}}}
{{{u=-1/2}}}
{{{sin(theta)=-1/2}}}
{{{theta=210}}} and {{{theta=330}}}