Question 707339
Prove 
sin^2x+cot^2x+cos^2x=csc^2x
start with left side:
sin^2x+cot^2x+cos^2x
Identity:sin^2x+cos^2x=1
cot^2x+1
Identity:cot^2x=csc^2x-1
cot^x+1
=csc^2x-1+1
=csc^2x
verified: left side=right side