定义域(x"竖线"x∈R,x≠5π/18+kπ/3, k∈Z), 对值域R,对周期是π/3, 对奇函数, 错,这个是非奇非偶函数 f(5π/18)无意义, f(-5π/18)有意义 不满足 f(-x)=f(x)或f(-x)=-f(x)(-5π/18+kπ/3,5π/18+kπ/3). 错增区间 kπ-π/2<3x-π/3< kπ+π/2 kπ-π/6<3x< kπ+5π/6 kπ/3-π/18 增区间 (-π/18+kπ/3,5π/18+kπ/3),k∈Z