0.526R<asinA+bsinB<3.835R
asinA+bsinB=2R[sin²(60°-B)+sin²B]
=2R(2cos²B+(√3/2)sinBcosB)
=2R[[4sin(φ-2B)/√19]+1].其中sinφ=4/√19.
0°<B<60°.-53°24′48〃<φ-2B<66°35′12〃,即可算出答案.
0.526R<asinA+bsinB<3.835R
asinA+bsinB=2R[sin²(60°-B)+sin²B]
=2R(2cos²B+(√3/2)sinBcosB)
=2R[[4sin(φ-2B)/√19]+1].其中sinφ=4/√19.
0°<B<60°.-53°24′48〃<φ-2B<66°35′12〃,即可算出答案.