题目

     Robots are being used for the first time in hospitals. “ Robot-nurses ” perform a variety of tasks each as delivering medicine t food and laboratory samples to sickrooms and taking away waste. Patients aren't  treated by robots, as this is still done by medical staff. The idea is to employ robots to transport supplies between departments.      “ Nurses often have to break off from what they are doing to gather supplies,” says Peter  Seiff , who makes the robots called TUGs. Research shows any interruption in medical work can lead Lo errors—a nurse may forget w对a，b∈R，记max{a，b}＝，函数f(x)＝max{|x＋1|，|x－2|}(x∈R)的最小值是_______