设函数f(x)=sin(xω+ψ)+cos(ωx+ψ)(ω>0,ψ绝对值<2分之π)的最小值正周期为π,且f(-x)=f(x)则 (A) f(x)在(0,2分之π)单间递减 (B) f(x)在(四分之π,4分之3π)单调递减 (C) f(x)在(0,2分之

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设函数f(x)=sin(xω+ψ)+cos(ωx+ψ)(ω>0,ψ绝对值<2分之π)的最小值正周期为π,且f(-x)=f(x)则 (A) f(x)在(0,2分之π)单间递减 (B) f(x)在(四分之π,4分之3π)单调递减 (C) f(x)在(0,2分之
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设函数f(x)=sin(xω+ψ)+cos(ωx+ψ)(ω>0,ψ绝对值<2分之π)的最小值正周期为π,且f(-x)=f(x)则 (A) f(x)在(0,2分之π)单间递减 (B) f(x)在(四分之π,4分之3π)单调递减 (C) f(x)在(0,2分之
设函数f(x)=sin(xω+ψ)+cos(ωx+ψ)(ω>0,ψ绝对值<2分之π)的最小值正周期为π,且f(-x)=f(x)
则 (A) f(x)在(0,2分之π)单间递减 (B) f(x)在(四分之π,4分之3π)单调递减 (C) f(x)在(0,2分之π)单调递增 (c)f(x)(4分之π,4分之3π)单调递增

设函数f(x)=sin(xω+ψ)+cos(ωx+ψ)(ω>0,ψ绝对值<2分之π)的最小值正周期为π,且f(-x)=f(x)则 (A) f(x)在(0,2分之π)单间递减 (B) f(x)在(四分之π,4分之3π)单调递减 (C) f(x)在(0,2分之
f(x)=sin(xω+ψ)+cos(ωx+ψ)
=√2sin(xω+ψ+π/4)
f(-x)=√2sin(-xω+ψ+π/4)
所以sin(xω+ψ+π/4)=sin(-xω+ψ+π/4)
2π/ω=π
ω=2
sin(2x+ψ+π/4)=sin(-2x+ψ+π/4)
sin(2x+ψ+π/4)+sin(2x-ψ-π/4)=0
2sin(2x)cos(2x+ψ+π/4)=0
cos(2x+ψ+π/4)=0
2x+ψ+π/4=kπ+π/2
2x+ψ=kπ+π/4
所以
f(x)=√2sin(xω+ψ+π/4)
=√2sin(kπ+π/2)