How to simplify these two expressions?

1.   (csc^2(x) - cot^2(x)) / (sin(-x)cot(x)

      Remember that  1 + cot^2 (x)  = csc^2 (x)

      So  csc^2 (x) - cot^2(x)  =  1

      Also   sin (-x)  =   - sin (x)

So  we have

1 / [ - sin (x) (cos (x)  / sin (x) ]  =

1 / (-cos (x) )  =    -  sec (x)

2.  sin ^2 (x)cos^2(x)  - cos^2(x)  =

(1  - cos^2(x) ) (cos^2 (x) ) -  cos^2(x)

cos^2(x) - cos^4 (x)   - cos^2(x)

-cos^4(x)