函数y=√2sin(3x+π/4)-1的单调递减区间为?

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函数y=√2sin(3x+π/4)-1的单调递减区间为?

函数y=√2sin(3x+π/4)-1的单调递减区间为?
函数y=√2sin(3x+π/4)-1的单调递减区间为?

函数y=√2sin(3x+π/4)-1的单调递减区间为?
y'=3√2cos(3x+π/4)令小于0,即:cos(3x+π/4)≤0解得:
2kπ≤3x+π/4≤(2k+1)π即:
(2kπ-π/4)/3≤x≤((2k+1)π-π/4)/3,k∈Z.

3x+π/4属于【π/2+2kπ,3π/2+2kπ】 (k属于Z),x的范围既是