Question

计算:sin方60°=_________,sin方60°+tan45°=________.

Answer 1

cos120=cos2*60=1-2sin^2(60)

sin^2(60)=(1/2)[1-cos120]

=(1/2)[1-(-1/2)]

=(1/2)(3/2)

=3/4

(2)

sin^2(60)=3/4

tan45=1

所以,

sin^2(60)+tan45=(3/4)+1=7/4