Question 966723


{{{ cos(x)/(1+sin(x)) = (1-sin(x))/cos(x )}}}

{{{ cos(x)*cos(x)= (1-sin(x))(1+sin(x)) }}}

{{{ cos^2(x)= 1-sin^2(x)}}}=>{{{1=sin^2(x)+cos^2(x)}}}=>{{{cos^2(x)=1-sin^2(x)}}}

{{{ cos^2(x)= cos^2(x)}}}