Question

ПОМОГИТЕ РЕШИТЬ!!!    $frac{1-cos ^{2 } alpha }{sin alpha *cos alpha } *ctg alpha$

Answer 1

$frac{1-cos^2 alpha }{sin alpha cos alpha } *ctg alpha = frac{sin^2 alpha }{sin alpha cos alpha } frac{cos alpha }{sin alpha } =frac{sin alpha }{cos alpha } frac{cos alpha }{sin alpha } =1$