1.x + y + z = p ,x,y,z均为正数证明:当x=y=z时 xyz 的值最大2.周长相等的三角形,正三角形面积最大

条件概率P(x|y)*P(y|z)=P(x|z) (x+y-z)(x-y+z)= X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 什么样的概率有这样的分布性质.p(z>x+y)=p(z>x)p(z>y):x,y>0 z+=x>y?++x: x=y; y=z; z=x/y 大大们写一下,注释啊,求class Point {double x,y,z;Point(double _x,double _y,double _z) {x = _x;y = _y;z = _z;}void setX(double _x) {x = _x;}double getDistance(Point p) {return (x - p.x)*(x - p.x) + (y - p.y)*(y - p.y) + (z - p.z)*(z - p.z);}} 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? x/(y+z+u)=y/(z+u+x)=z/(u+y+x)=u(x+y+z)求(x+y)/(z+u)+(y+z)/(y+x)+(z+y)/(x+y)+(u+x)/(z+y) 1.设有比例式：x/(y+z)=y/(x+z)=z/(x+y),有比例性质,得x/(y+z)=y/(x+z)=z/(x+y)=（x+y+z)/[(y+z)+(x+z)+(x+y)]=0.5x/(y+z)=y/(x+z)=(x-y）/[（y+z）-（x+z)]=-1,由此可得0.5=-1试分析推理产生错误的原因 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) 已知 (x+y-z)/z=(x-y+z)/y=(y+z-x)/x,且xyz≠0,求代数式 ((x+y)(y+z)(x+z))/xyz x分之y+z=y分之z+x=z分之x+y(x+y+z不等于0）,求x+y+z分之x+y-z