海天间一叶孤舟
幼苗
共回答了17个问题采纳率:82.4% 举报
1,f(x)=√3sin2x+2cos²x+m
=√3sin2x+1+cos2x+m
=2sin(2x+π/6)+m+1
∵0≤x≤π/2 ∴π/6≤2x+π/6≤7π/6
那么f(x)max=2+m+1=6,m=3
令2x+π/6=(2k+1)π,那么x=kπ+5π/12
那么对称中心为(kπ+5π/12,4) (k∈Z)
2,设点(x,y)在f1(x)上,那么点(-x,y)在f(x)上
那么y=f1(x)=f(-x)=2sin(-2x+π/6)+4=-2sin(2x-π/6)+4
那么f2(x)=-2sin[2(x-π/4)-π/6]+4=-2sin(2x-2π/3)+4
令2kπ-π/2≤2x-2π/3≤2kπ+π/2
kπ+π/12≤x≤kπ+7π/12
那么函数f2(x)的单调递减区间为[kπ+π/12,kπ+7π/12] (k∈Z)
1年前
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