高中数学三角函数

显示全部楼层 · 2012-9-18 12:24:19

(1)f[x]=sin[x+π/6]+sin[x-π/6]+cosx+a =sinxcos[π/6]+cosxsin[π/6]+sinxcos[π/6]-cosxsin[π/6]+cosx+a =2sinxcos[π/6]+cosx+a =√3sinx+cosx+a =2sin[x+π/6]+a 当sin[x+π/6]=1,f[x]取到最大值为f[x]max=2+a=1 a=-1 (2)f[x]=2sin[x+π/6]-1 令u=x+π/6，则sinu 的单调增区间是[-π/2+2kπ，π/2+2k...

千问 · 2012-9-18 12:24:19

f(x)=sin(x+ π/6) +sin(x-π/6) +acosx +b(a,b∈r,且均为常数）=2sinxcosπ/6+acosx+b=√3sinx+acosx+b=√(3+a^2)sin(x+θ)+b(sinθ=a/√(3+a^2),cosθ=√3/√(3+a^2),f（x)在区间[-π/3,0]上单调递增，且恰好能够取到f(x...

千问 · 2012-9-18 12:24:19