Question

упростите выражение косинус квадрат альфа минус котангенс квадрат альфа деленное на синус квадрат альфа минус тангенс квадрат альфа​

Answer 1

Ответ:

$ctg^{6}\alpha$

Объяснение:

$\frac{cos^{2}\alpha-ctg^{2}\alpha}{sin^{2}\alpha-tg^{2}\alpha}=\frac{cos^{2}\alpha-\frac{cos^{2}\alpha}{sin^{2}\alpha}}{sin^{2}\alpha-\frac{sin^{2}\alpha}{cos^{2}\alpha}}=\frac{cos^{2}\alpha*sin^{2}\alpha-cos^{2}\alpha}{sin^{2}\alpha}:\frac{sin^{2}\alpha*cos^{2}\alpha-sin^{2}\alpha}{cos^{2}\alpha}=$

$=\frac{cos^{2}\alpha(sin^{2}\alpha-1)}{sin^{2}\alpha}*\frac{cos^{2}\alpha}{sin^{2}\alpha(cos^{2}\alpha-1)}=\frac{-cos^{2}\alpha(1-sin^{2}\alpha)}{sin^{2}\alpha}*\frac{cos^{2}\alpha}{-sin^{2}\alpha(1-cos^{2}\alpha)}=$

$=\frac{cos^{2}\alpha*cos^{2}\alpha}{sin^{2}\alpha}*\frac{cos^{2}\alpha}{sin^{2}\alpha*sin^{2}\alpha}=\frac{cos^{2}\alpha*cos^{2}\alpha*cos^{2}\alpha}{sin^{2}\alpha*sin^{2}\alpha*sin^{2}\alpha}=\frac{cos^{6}\alpha}{sin^{6}\alpha}=ctg^{6}\alpha;$