Tg( 270 -x) × sin( 810 - x ) ×sin (900 + x)если sin х = 0.3

Question

Tg( 270 -x) × sin( 810 - x ) ×sin (900 + x)
если sin х = 0.3

Answer 1

=ctg(x)*cos(x)*(-sin(x))=-cos²x= - 0.91

cos²x=1-sin²x=1-0.09=0.91