Answer:
Step-by-step explanation:
recall again, sin²(θ) + cos²(θ) = 1.
ok is there more info about it
![\bf sin(x)[csc(x)-sin(x)]~~=~~cos^2(x) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ sin(x)\left[\cfrac{1}{sin(x)}-\cfrac{sin(x)}{1} \right]\implies \underline{sin(x)}\left[\cfrac{1-sin^2(x)}{\underline{sin(x)}} \right] \\\\\\ 1-sin^2(x)\implies cos^2(x)](https://tex.z-dn.net/?f=%5Cbf%20sin%28x%29%5Bcsc%28x%29-sin%28x%29%5D~~%3D~~cos%5E2%28x%29%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20sin%28x%29%5Cleft%5B%5Ccfrac%7B1%7D%7Bsin%28x%29%7D-%5Ccfrac%7Bsin%28x%29%7D%7B1%7D%20%5Cright%5D%5Cimplies%20%5Cunderline%7Bsin%28x%29%7D%5Cleft%5B%5Ccfrac%7B1-sin%5E2%28x%29%7D%7B%5Cunderline%7Bsin%28x%29%7D%7D%20%5Cright%5D%20%5C%5C%5C%5C%5C%5C%201-sin%5E2%28x%29%5Cimplies%20cos%5E2%28x%29)
