已知:x=根号3+1,y=根号3-1,求x^2-2xy+y^2分之x^2-y^2

问题描述:

已知:x=根号3+1,y=根号3-1,求x^2-2xy+y^2分之x^2-y^2

x=√3+1,y=√3-1
x-y=√3+1-√3+1=2
x+y=√3+1+√3-1=2√3
∴ ﹙x²-y²﹚/﹙x²-2xy+y²﹚
=﹙x-y﹚﹙x+y﹚/﹙x-y﹚²
=﹙x+y﹚/﹙x-y﹚
=2√3/2
=√3.