Question

设函数f（x）=│sin(x+60）│,则求f（x）的单调区间

Answer 1

画图知

|sinx|的单调增区间为

kπ≤x≤π/2+kπ

减区间为π/2+kπ≤x≤π+kπ

所以│sin(x+60）│的单调增区间为

kπ≤x+π/3≤π/2+kπ

即kπ-π/3≤x≤π/6+kπ

减区间为π/2+kπ≤x+π/6≤π+kπ

kπ-π/3≤x≤5π/6+kπ

k∈Z