Упростите tga/sina-sina/ctga-sina*ctga

Question

Упростите
tga/sina-sina/ctga-sina*ctga

Answer 1

Tga/sina-sina/ctga-sina*ctga=sina/(cosa*sina)-(sina)^2/cosa-(sina*cosa)/sina=1/cosa-(sina)^2/cosa-cosa=(1-sina^2-cosa^2)/cosa=(cosa^2-cosa^2)/cosa=0