Question 971395
Verify each identity 
(1 over 1 + cosx) + ( 1 over 1 - cos x) = 2 csc^2 x
start with left side:
{{{(1/(1+cosx))+(1/(1-cosx))}}}
lcd:(1+cosx)(1-cosx)
{{{(1/(1+cosx))+(1/(1-cosx))=(1-cosx+1+cosx)/(1+cosx)(1-cosx)
=2/(1+cos^2(x))=2/(sin^2(x))=2csc^2(x)}}}
verified: left side=right side