Question

найдите sin a , если sin a/2=0.6

Answer 1

$sinfracalpha2=sqrt{frac{1-cosalpha}2}\sqrt{frac{1-cosalpha}2}=0,6\frac{1-cosalpha}2=0,36\1-cosalpha=0,72\cosalpha=0,28\sin^2alpha+cos^2alpha=1\sinalpha=sqrt{1-cos^2alpha}=sqrt{1-0,0784}=sqrt{0,9216}=0,96$