Question 595403
You'll then use the identity 


csc^2(x) - cot^2(x) = 1



But you first need to factor out a negative 1 to go from 


cot^2x - csc^2x 


to 


-1(-cot^2x + csc^2x )



which rearranges to 



-1(csc^2x-cot^2x)



Now use the identity listed at the top of the page to get 


-1*1


-1



So the entire expression simplifies to <font color="red">-1</font>