求函数y=tan(x⼀2+派⼀3的定义和单调区间

2024-12-26 18:43:19
推荐回答(2个)
回答1:

在(kπ-π/2,kπ+π/2)单调递增
令x/2+π/3≠kπ-π/2 解得x≠2kπ-5π/3
x/2+π/3≠kπ+π/2 解得x≠2kπ+π/3
所以当x≠2kπ-5π/3或x≠2kπ+π/3时函数有意义

令kπ-π/2<x/2+π/3<kπ+π/2解得2kπ-5π/3<x<2kπ+π/3
所以函数y=tan(x/2+π/3)的单调增区间为(2kπ-5π/3,2kπ+π/3)

回答2:

1.先求定义域:令x/2+π/3≠kπ+π/2 (k为任意整数), 解得x≠2kπ+(π/3),所以此函数的定义域为{x|x≠2kπ+(π/3),x属于R}
2.因为y=tanx的单调区间为(kπ-π/2,kπ+π/2)(k为任意整数), 而y=tan(x/2+π/3)的周期为2π,y=tan(x/2+π/3)的图象可以看成是由y=tanx的图象向左平移π/3个单位,再将横坐标扩大到原来的2倍得到的,所以此函数的单调区间可以这样求解:
令kπ-π/2<x/2+π/3<kπ+π/2解得2kπ-5π/3<x<2kπ+π/3
所以函数y=tan(x/2+π/3)的单调增区间为(2kπ-5π/3,2kπ+π/3)(k为任意整数)