Question #8e1d5

1 Answer
Jul 27, 2016

sqrt((1/2)(1-((sqrt 3 + 1)/(2 sqrt 2))))

=0.1305, nearly

Explanation:

Angle is in degree unit.

sin(15/2)

=sqrt((1-cos 15)/2)

=sqrt((1/2)(1-cos(45-30))

=sqrt((1/2)(1-(cos 45 cos 30+sin 45 sin 30))

=sqrt((1/2)(1-((1/sqrt 2)(sqrt 3/2)+(1/sqrt 2)(1/2)))

=sqrt((1/2)(1-((sqrt 3 + 1)/(2 sqrt 2))))

0.1305, nearly