已知x=根号5-根号3⼀2,y=根号5+根号3⼀2, 求代数式x的平方-3xy+y的平方的值

2025-06-21 15:29:26
推荐回答(1个)
回答1:

x^2-3xy+y^2
=(x-y)^2-xy
=[√5-√3/2-(√5+√3/2)]^2-(√5-√3/2)(√5+√3/2)
=(-√3)^2-(5-3/4)
=3-17/4
=-29/4