Упростите. (tgx:sec x)^2+(ctgx:cosecx)^2-cos^2x

Question

Упростите. (tgx:sec x)^2+(ctgx:cosecx)^2-cos^2x

Answer 1

Secx=1/cosx cosecx=1/sinx
(sinx/cosx:1/cosx)²+(cosx/sinx:1/sinx)²-cos²x=sin²x+cos²x-cos²x=sin²x