Question

упростите
$frac{1 - cos ^{2}7y }{cos ^{2}7y }$
$(1 - cosx)(1 + cosx) times ctg ^{2} x$
$sqrt{1 - cos ^{2} beta }$
​

Answer 1

$frac{sin^{2}7y }{cos^{2} 7y} =tg^{2}7y$

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

║sinx║