已知函数,.(Ⅰ)讨论单调区间;(Ⅱ)若直线是函数图象的切线,求的最小值. 答案:【答案】(Ⅰ)见解析;(Ⅱ).【解析】(Ⅰ)求导后,讨论、、时、的解集即可得解;(Ⅱ)设切点为,利用导数的几何意义求得切线方程,由题意,,令,求导后求得的最小值即可得解.(Ⅰ)由题意,则,令,①当时,,函数在上单调递增;②当时,,若即,即,函数在上单调递增;若即,令可16、---What do you think I should do?
---I think you’d better invite him back to our
party
A.out of respect
B.at the expense
C.beyond control
D.in favor