先化简再求值(根号3-根号2)^2-根号2*(根号8-3根号3)
问题描述：
先化简再求值(根号3-根号2)^2-根号2*(根号8-3根号3)
（结果精确到0.01,根号6≈2.45,根号3≈1.73,根号2≈1.41
答
(根号3-根号2)^2-根号2*(根号8-3根号3)
=3-2√6+2-4+3√6
=1+√6
≈1+2.45
=3.45已知x=根号2+1分之1,y=根号2-1分之1,求x^2+xy+y^2x=根号2+1分之1=（√2-1）/[(√2+1)(√2-1)]=√2-1y=根号2-1分之1=(√2+1)/[(√2-1)(√2+1)]=√2+1x^2+xy+y^2=(x²+2xy+y²)-xy=(x+y)²-xy=(√2-1+√2+1)²-(√2-1))(√2+1)=(2√2)²-(2-1)=8-1=7