Question

упростить выражение,очень срочно!!

Answer 1

$frac{ctg^2(a + frac{pi}{2}) * cos^2(a - frac{pi}{2} ))} {ctg^2(a - frac{pi}{2} ) - cos^2(a + frac{pi}{2} )}$

$frac{tg^2(a ) * sin^2(a))} {tg^2(a) - sin^2(a)}$

$frac{ frac{sin^2(a)}{cos^2(a)} * sin^2(a))} { frac{sin^2(a)}{cos^2(a)} - sin^2(a)}$

$frac{sin^4(a)} { sin^2(a) - cos^2(a)sin^2(a)}$

$frac{sin^4(a)} {sin^2(a)( 1 - cos^2(a))}$

$frac{sin^2(a)} {1 - cos^2(a)}$

$frac{sin^2(a)} {sin^2(a)} = 1$