Question

How to verify with steps?

Answer 1

`csc(-x)-1~~ = ~~\cfrac{cos^2(x)}{csc(-x)+1} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{cos^2(x)}{csc(-x)+1}\implies \cfrac{1-sin^2(x)}{(1)/(sin(-x)+1)}\implies \cfrac{1-sin^2(x)}{(1)/(-sin(x)+1)}\implies \cfrac{[1-sin(x)][1+sin(x)]}{ ~~ (-1+sin(x))/(sin(x)) ~~ } \\\\\\\ [1-sin(x)][1+sin(x)]\cdot \cfrac{sin(x)}{-1+sin(x)} \\\\\\\ [1-sin(x)][1+sin(x)]\cdot \cfrac{sin(x)}{-[1-sin(x)]} \\\\\\\ [1+sin(x)][-sin(x)] \implies \boxed{-sin(x)-sin^2(x)} \\\\[-0.35em] ~\dotfill`

`csc(-x)-1\implies \cfrac{1}{sin(-x)}-1\implies \cfrac{1}{-sin(x)}-1\implies \boxed{\cfrac{-1-sin(x)}{sin(x)}}`

now, as you can see is a no dice, before doing many simplifications, I often check them graphically, so I know what's cooking, anyhow, Check the picture below, they are definitely not the same, the red one is the one on the right-hand-side.