分解因式x三次方+y三次方+z三次方-3xyz 答案 x^3+y^3+z^3-3xyz =x^3+x^2y+x^2z+y^2x+y^3+y^2z+z^2x+z^2y+z^3-x^2y-y^2x-xyz-xyz-y^2z-yz^2-x^2z-xyz-z^2x=x^2(x+y+z)+y^2(x+y+z)+z^2(x+y+z)-xy(x+y+z)-yz(x+y+z)-zx(x+y+z)=(x+y+z)(x^2+y^...
x^3+y^3+z^3-3xyz =x^3+x^2y+x^2z+y^2x+y^3+y^2z+z^2x+z^2y+z^3-x^2y-y^2x-xyz-xyz-y^2z-yz^2-x^2z-xyz-z^2x=x^2(x+y+z)+y^2(x+y+z)+z^2(x+y+z)-xy(x+y+z)-yz(x+y+z)-zx(x+y+z)=(x+y+z)(x^2+y^2+z^2-xy-yz-zx). 解析看不懂?免费...
=x^2(x+y+z)+y^2(x+y+z)+z^2(x+y+z)-xy(x+y+z)-yz(x+y+z)-zx(x+y+z)=(x+y+z)(x^2+y^2+z^2-xy-yz-zx) 解析看不懂?免费查看同类题视频解析查看解答 相似问题 x的立方+y的立方+z的立方-3xyz 因式分解, 分解因式x三次方+y三次方+z三次方-3xyz x^3+y^3+z^3-3xyz...
结果一 题目 证明x三次方+y三次方+z三次方>=3xyz 答案 x^3+y^3+z^3-3xyz=(x+y+z)(x^2+y^2+z^2-xy-yz-zx)=(x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]/2≥0x^3+y^3+z^3≥3xyz相关推荐 1证明x三次方+y三次方+z三次方>=3xyz ...
答案应该为D：3XYZ 不过，楼主的题目中可能遗漏了Z的三次方。应该是：x^3+y^3+z^3=？解答：x^3+y^3+z^3-3xyz =(x+y+z)(x^2+y^2+z^2-xy-yz-xz)因x+y+z=0，故有x^3+y^3+z^3-3xyz=0*(x^2+y^2+z^2-xy-yz-xz)=0 即x^3+y^3+z^3=3xyz 所以选D 3XYZ ...
两边同时对x求偏导,得 3z² az/ax-3yz-3xy az/ax=0 z² az/ax-yz-xy az/ax=0 az/ax= yz/（z²-xy）同理 两边同时对y求偏导,得 3z² az/ay-3xz-3xy az/ay=0 z² az/ay-xz-xy az/ay=0 az/ay= xz/（z²-xy）
求z对x的积分,求z对y的积分 相关知识点: 试题来源: 解析 两边同时对x求偏导,得3z² az/ax-3yz-3xy az/ax=0z² az/ax-yz-xy az/ax=0az/ax= yz/(z²-xy)同理两边同时对y求偏导,得3z² az/ay-3xz-3xy az/ay=0z² az/ay-xz-xy az/ay=0az/ay= xz/(z²-xy)...
分解因式x三次方+y三次方+z三次方-3xyz 解: x^3+y^3+z^3-3xyz =x^3+x^2y+x^2z+y^2x+y^3+y^2z+z^2x+z^2y+z^3-x^2y-y^2x-xyz-xyz-y^2z-yz^2-x^2z-xyz-z^2x =x^2(x+y+z)+y^2(x+y+z)+z^2(x+y+z)-xy(x+y+z)-yz(x+y+z)-zx(x+y+z... 淘宝云端彼岸婚纱旅...
答案 因为(x+y+z)(x2+y2+z2-xy-yz-zx)=x3+y3+z3-3xyz 又x+y+z=0 所以 x3+y3+z3-3xyz=0 即 x3+y3+z3=3xyz. 相关推荐 1 数学问题:已知X+Y+Z=0.那么为什么X的三次方+Y的三次方+Z的三次方=3XYZ? 反馈 收藏
先写出(x+y+z)^3的展开式，慢慢乘，然后得 x^3+y^3+z^3=-3(x+y)(x+z)(y+z)x+y+z=0 x+y=-z y+z=-x x+z=-y x^3+y^3+z^3=3xyz