Question

СРОЧНО!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

Ответ:

Объяснение:

$1)sin^2\alpha +cos^2\alpha =1\\sin\alpha =-\sqrt{1-cos^2\alpha }=-\sqrt{1-0.8^2 }=-\sqrt{1-0,64}=-0,6$

$2)sin2\alpha=2sin\alpha *cos\alpha =2*(-0,6)*0,8=-1,2*0,8=-0,96\\ 3) cos(\alpha +\frac{\pi }{3})=cos\alpha *cos\frac{\pi }{3}-sin\alpha *sin\frac{\pi }{3}=0,8*\frac{1}{2}+(-0,6)*\frac{\sqrt{3} }{2}=0,4-0,3\sqrt{3}=-4,79$