Question 829038
{{{ ((cos(x)*cot(x))/csc(x))-1 = -sin^2(x) }}}
Multiply by {{{csc(x)}}},
{{{ cos(x)*cot(x)-csc(x) = -sin^2(x)*(1/sin(x)) }}}
{{{ cos(x)*cot(x)-csc(x) = -sin(x) }}}
{{{ cos(x)*(cos(x)/sin(x))-1/sin(x) = -sin(x) }}}
Multiply both sides by {{{sin(x)}}},
{{{ cos(x)*cos(x)-1 = -sin(x)*sin(x) }}}
{{{ cos^2(x)+ sin^2(x)=1 }}}