f(x)=sin(x+π/6)+1-cosx
=(根号3/2)sinx+(1/2)cosx+1-cosx
=(根号3/2)sinx-(1/2)cosx+1
=sin(x-π/6)+1
又f(A)=1 A∈(0,π)
所以sin(A-π/6)=0 A=π/6
又c=3 a=1
由余弦定理知1=b*2+c*2-2bc*cos(π/6)
b*2-3b+2=0 得b=1或2
你是题目中打错了很多字,我猜了很长时间.先猜题,再做题.
f(x)=sin(x+π/6)+1-cosx
=(根号3/2)sinx+(1/2)cosx+1-cosx
=(根号3/2)sinx-(1/2)cosx+1
=sin(x-π/6)+1
又f(A)=1 A∈(0,π)
所以sin(A-π/6)=0 A=π/6
又c=3 a=1
由余弦定理知1=b*2+c*2-2bc*cos(π/6)
b*2-3b+2=0 得b=1或2
你是题目中打错了很多字,我猜了很长时间.先猜题,再做题.