若x+1/x=5,则(根号x)减去1/(根号x)等于多少?谁回答的对就给谁分(请注明详细解答过程)

Question

若x+1/x=5,则(根号x)减去1/(根号x)等于多少?谁回答的对就给谁分(请注明详细解答过程)

Answer 1

令 √x - 1/√x = a
则,a²=x + 1/x - 2 = 5-2 = 3
a=±√3
即√x - 1/√x = ±√3