Question

1-sin^2L(1+ctg^2L) упростите

Answer 1

$1-sin^2\alpha (1+ctg^2\alpha )=1-sin^2\alpha (1+\frac{cos^2\alpha}{sin^2\alpha})=1-sin^2\alpha-cos^2\alpha=1-(sin^2\alpha+cos^2\alpha)=1-1=0$