Question

在三角形ABC中,已知b^2=ac,且a^2-c^2=ac-bc.(1)求角a?(2)求bsinB/C的值?

Answer 1

^2＝ac,

a^2-c^2＝ac-bc,

a^2=b^2+c^2-bc,

b^2+c^2=a^2+bc,

cosA=(b^2+c^2-a^2)/2bc=1/2,

A=60度,

a/sinA=b/sinB,

sinB=bsin60/a=b√3/2a,

(bsinB)/c=b*b√3/2ac=√3/2.