求单调递增区间

Question

具体步骤

Answer 1

y = sin (-2x - π/6) = - sin (2x + π/6)
单调增区间：
2kπ + π/2 ≤ 2x + π/6 ≤ 2kπ + 3π/2
2kπ + π/3 ≤ 2x ≤ 2kπ + 4π/3
kπ + π/6 ≤ x ≤ kπ + 2π/3