求下列函数的单调区间(1)y=sin(3x-π/3)(2)y=-cos(2x-π/3)

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求下列函数的单调区间(1)y=sin(3x-π/3)(2)y=-cos(2x-π/3)
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求下列函数的单调区间(1)y=sin(3x-π/3)(2)y=-cos(2x-π/3)
求下列函数的单调区间(1)y=sin(3x-π/3)(2)y=-cos(2x-π/3)

求下列函数的单调区间(1)y=sin(3x-π/3)(2)y=-cos(2x-π/3)
(1)由图像可得,当-π/2+2kπ≤3x-π/3≤π/2+2kπ,即-π/18+2kπ/3≤x≤5π/18+2kπ/3时函数单调递增;
同理,当π/2+2kπ≤3x-π/3≤3π/2+2kπ,即5π/18+2kπ/3≤x≤11π/18+2kπ/3时函数单调递减.其中k∈Z.
(2)由图像可得,-π/2+2kπ≤2x-π/3≤2kπ,即-π/12+kπ≤x≤π/6+kπ时函数单调递减;
同理,当2kπ≤2x-π/3≤π/2+2kπ,即π/6+kπ≤x≤5π/12+kπ时函数单调递增.其中K∈Z.
这里把函数看成y=sinA和y=-cosB,这样问题就简单了.

(1)y=sin(3x-π/3)的周期T=2π/3,水平向右位移为π/3/3=π/9,则依据正弦函数的图像可知,{xI2kπ/3-π/6+π/9 (2)y=-cos(2x-π/3)的周期T=π,水平向右位移为π/3/2=π/6,则依据正弦函数的图...

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(1)y=sin(3x-π/3)的周期T=2π/3,水平向右位移为π/3/3=π/9,则依据正弦函数的图像可知,{xI2kπ/3-π/6+π/9 (2)y=-cos(2x-π/3)的周期T=π,水平向右位移为π/3/2=π/6,则依据正弦函数的图像可知,{xIkπ+π/6

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