x^2+y^2+z^2=1,则x+y的范围是___?答案是【负根号2,根号2】 要用到柯西不等式的,x^2+y^2+z^2=1,则x+y的范围是___?答案是【负根号2,根号2】要用到柯西不等式的,当然你不柯西不等式也可以，因为我用它

用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证? 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知xyz满足(x/y+z)+(y/z+x)+（z/x+y）=1,则代数式(x^2/y+z)+（y^2/z+x）+z^2/x+y的值为 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 分式加减的几道题目求速度1 .(x+y)²/（x-z)(y-z) - (y+z)²/（x-z)(y-z) = 2.2x+3y/x-y+2y/y-x-3y/x-y= 设f(x,y,z)=e^x*y*z^2,其中z=z(x,y)是由x+y=z+x*e^(z-x-y)确定的隐函数,则f'x(0,1,1)= 设正实数x,y,z满足x+2y+z=1,则1/(x+y)+9(x+y)/(y+z)的最小值 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 1、y-x/x²-y²2、(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z) 若x+y+z=3y=2z,则x/x+y+z=? 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 2|X-Y|+√2Y+Z+Z²-Z+1/4=0求X+Y+Z的值 设x,y,z是三个非零实数,且满足1/x+1/y+1/z=2,1/x*x+1/y*y+1/z*z,则1/x*y+1/y*z+1/z*x的值是多少?1/x*x+1/y*y+1/z*z=1 若x,y,z是正实数,且x+y+z=xyz,证明：(y+z/x)+(z+x/y)+(x+y/z)≥2倍的(1/x)+(1/y)+(1/z)的平方 已知x,y,z满足 2倍(x-y的绝对值)+(2y的平方根)-z+(z×z)=-1/4,求x,y,z的值 已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/(x+y)的值、2是平方