x^2+y^2=1,x^2+z^2=2,y^2+z^2=2,则xy+yz+xz最小值是多少？
详解，至少要关键步骤
參考答案:x^2+z^2=2
y^2+z^2=2
则x^2=y^2
x^2+y^2=1
则x^2=y^2=1/2
x^2+z^2=2
则z^2=3/2
全取正值时最大
1/2+根号3
x^2+y^2=1,x^2+z^2=2,y^2+z^2=2,则xy+yz+xz最小值是多少？
详解，至少要关键步骤
參考答案:x^2+z^2=2
y^2+z^2=2
则x^2=y^2
x^2+y^2=1
则x^2=y^2=1/2
x^2+z^2=2
则z^2=3/2
全取正值时最大
1/2+根号3