求下列函数的单调区间:(1)y=x2-5x-6 (2)y=9-x2,x∈[-2,3](3)y=-2x (4)y=|x+1

2024-12-24 14:29:06
推荐回答(1个)
回答1:

(1)∵y=x2-5x-6=(x-

5
2
2-
49
4

∴y=x2-5x-6单调增区间为[
5
2
,+∞);单调减区间为(-∞,
5
2
].
(2)∵y=9-x2,x∈[-2,3],
∴y=9-x2单调增区间为[-2,0];单调减区间为(0,3].
(3)∵y=-
2
x

∴其单调增区间为(-∞,0),(0,+∞).
(4)∵y=|x+1|,
∴其单调增区间为[-1,+∞);单调减区间为[-∞,-1].