Question

Найдите значение выражения:
(sin(15)^2 - sin(75)^2)/(sin(15) * cos(15))

Answer 1

1. sin²15-sin²75=sin²(90-75)-sin²75=cos²75-sin²75=cos(2*75)=cos150=cos(180-30)=-cos30=-√3/2

2. sin15*cos15=(1/2)*(2sin15*cos15)=(1/2)*sin(2*15)=(1/2)*sin30=(1/2)*(1/2)=1/4

3.  -(√3/2):(1/4)=-2√3