求函数y=2sin(3x+3/π)的周期,单调区间,最大值与最小值,并分别写出取到最大值与最小值时自变量x的集合

如题所述

解:T=2π/W 所以T=2π/3
单调增区间:2kπ - π/2 ≤ 3x + π/3 ≤ 2kπ + π/2
即:2kπ/3 - 5π/18 ≤ x ≤ 2kπ/3 + π/18
单调减区间:2kπ + π/2 ≤ 3x + π/3 ≤ 2kπ + 3π/2
即:2kπ/3 + π/18 ≤ x ≤ 2kπ3 + 7π/18
函数取最大值是y=2,{x/x=2kπ/3 + π/18}
函数去最小值是y=-2,{x/x=2kπ/3 - 5π/18}
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第1个回答  2012-12-08
1、周期:
3T = 2π
T = 2π/3
2、单调区间
(1)增函数:
2kπ - π/2 ≤ 3x + π/3 ≤ 2kπ + π/2
2kπ/3 - 5π/18 ≤ x ≤ 2kπ/3 + π/18
(2)减函数:2kπ + π/2 ≤ 3x + π/3 ≤ 2kπ + 3π/2
2kπ/3 + π/18 ≤ x ≤ 2kπ3 + 7π/18
3、最大值:
x = 2kπ/3 + π/18:y = 2
4、最小值:
x = 2kπ/3 - 5π/18:y = -2本回答被网友采纳
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