已知三角形ABC中,a:b:c=1:2:3,a=1,求a-2b+c/sinA+sinB+sinC

问题描述:

已知三角形ABC中,a:b:c=1:2:3,a=1,求a-2b+c/sinA+sinB+sinC

∵a:b:c=1:2:3,且a=1
∴b=2
c=3
a-2b+c
=1-4+3
=0
(a-2b+c)/(sinA+sinB+sinC)
=0