Question 881851
{{{tan(A)=1/tan(A)}}}
{{{tan^2(A)-1=0}}}
{{{(tan(A)-1)(tan(A)+1)=0}}}
Two solutions:
{{{tan(A)=1}}}
{{{A=pi/4}}} and {{{A=(5/4)pi}}}
and
{{{tan(A)=-1}}}
{{{A=(3/4)pi}}} and {{{A=(7/4)pi}}}