Prove: (csc x + cot x)(sec x -1) = tan?

The question asked me to graph the left hand side on a calculator to get the right hand side and when I do, my calc shows me a tan function. The problem is, when I try and prove the l.h.s, I always wind up with cos/sin (or cot) at the end. I'm almost positive I graphed it right, so where have I gone wrong?