题目

The COVID-19 has led to a great demand for bikes and biking.Bike stores are struggling hard to keep up with the demand.In the United States,bike sales have seen their biggest jump since the 1970s.Sales of adult bikes in April of 2020 were three times as high as last year.The situation is similar in Asia and Europe.Around 90%of the bikes sold in the US are made in China.But because of the COVID-19,even the normal supply of bicycles wasn’t being created.That demand began to go up in mid-March,as people began looking for ways of getting around that didn’t involve crowded public transportation（本小题满分12分）设函数（）．（1）当时，讨论函数的单调性；（2）若对任意及任意，，恒有成立，求实数的取值范围．