Question 767185
Verify each trig equation by subtituting identities to match the right hand side of the equation to the left hand side of the equation. 
(sinx/ 1- cosx) + (sinx/1+cosx) = 2 csc x
start with left hand side
{{{sin(x)/(1-cos(x))+sin(x)/(1+cos(x))}}}
{{{(sin(x)*(1+cos(x))+sin(x)*(1-cos(x)))/(1-cos^2(x))}}}
{{{(sin(x)*(1+cos(x))+sin(x)*(1-cos(x)))/(sin^2(x))}}}
cancel out sin(x)
{{{(1+cos(x)+1-cos(x))/(sin(x))}}}
{{{(2)/(sin(x))=2csc(x)}}}
verified:left hand side=right hand side