函数y=sin(-1⼀2x+π⼀4)的单调区间

2025-02-14 07:33:43
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回答1:

函数y=sin[-(1/2)x+π/4]=sin{-[(1/2)x-π/4]}=-sin[(1/2)x-π/4]的单调区间
解:单增区间:由2kπ+π/2≦(1/2)x-π/4≦2kπ+3π/2,
得 2kπ+3π/4≦(1/2)x≦2kπ+7π/4,得单增区间为:4kπ+3π/2≦x≦4kπ+7π/2;
单减区间:由2kπ-π/2≦(1/2)x-π/4≦2kπ+π/2.
得 2kπ-π/4≦(1/2)x≦2kπ+3π/4,得单减区间为:4kπ-π/2≦x≦4kπ+3π/2;