limxy(x^2-y^2) (x^2 y^2)

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limxy(x^2-y^2) (x^2 y^2)
多元函数极限limxy√(x∧2+y∧2),趋近原点.为什么可以用|xy|<x∧2+y∧2,这样求出来的极限应该是带绝对

x^2+Y^2>=0,这是肯定的啊,|xy|<x∧2+y∧2成立,|xy|绝对值里面大于0,成立,她小于零,也成立啊,所以去掉和不去掉,都一样,再计算时,你直接去掉就行

x^2-y^2/x+y-4x(x-y)+y^2/2x-y,

(x^2-y^2)/(x+y)-(4x(x-y)+y^2)/(2x-y)=(x-y)(x+y)/(x+y)-(4x^2-4xy+y^2)/(2x-y)=(x-y)-(2x-y)^2/(2x-y)=(x

计算(x+y)(x+y)^2(-x-y)^3

(x+y)(x+y)^2(-x-y)^3=-(x+y)^6

计算:(x-y)^2*(y-x)^2*(x-y)^6

(x-y)^2*(y-x)^2*(x-y)^6=(x-y)^2*(x-y)^2*(x-y)^6=(x-y)^10再问:能详细一点吗?我,初一的再答:(x-y)^2=(y-x)^2=(x-y)^2*(x

1、x(x-y)(x+y)-x(x+y)^2

1)x(x-y)(x+y)-x(x+y)^2=x((x-y)(x+y)-(x+y)^2)=x(x^2-y^2-x^2-2xy-y^2)=x(-2xy-2y^2)=-2xy(x+y)2)(2a+b)(2

【(x-y)^2+(x+y)(x-y)】除以 2x

【(x-y)^2+(x+y)(x-y)】除以2x=(x-y)*(x-y+x+y)/2x=(x-y)*2x/2x=x-y

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y

[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y=[x²-y²-x²-2xy-y²-xy+xy²]/(y/2)=[(x-2)y

6(x+y)2-2(x-y)(x+y)因式分解

(x+y)ˆ2-2(x+y)(x-y)+(x-y)ˆ2=(x+y-x+y)^2=(2y)^4=4y^2如果满意请点击右上角评价点【满意】即可~再问:这个我看不懂,能不能写下来啊,谢

[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013

先一个一个的展开括号项,再同项合并就行了啊[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x=[xx-xy-(xy-yy)+x(x-y)+y(x-y)]÷2x=[xx-xy-xy+yy+xx-

二元微积分求极限limxy(x^2-y^2)/(x^2+y^2)根号(x^2+y^2) (x,y趋向于0)怎么算

lim0>xy(x^2-y^2)/(x^2+y^2)^(3/2),是这个?x=rcost;y=rsint;r->0xy(x^2-y^2)/(x^2+y^2)^(3/2)=r^2sintcost*r^2

化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方

(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方=x²-2xy-3y²-x²+4y²-x²+2xy-y²=(x²-

(2x-y)^2-4(x-y)(x+2y)

4x^2+y^2-4xy-4(x^2-xy+2xy-2y^2)展开化简吧!

[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y)

=(x-y)[(3x+y)-(2x+3y)]*(x-y)=(x-y)*(x-y)(3x+y-2x-3y)=(x-y)(x-y)(x-2y)到底是化简,还是?=(x*x-2xy+y*y)(x-2y)=x

(1)(x^2/x)-y-x-y

(1)x^2/x)-y-x-y=x-y-x-y=-2y(2)(a/a-b)-(a/a+b)-(2b^2/a^2-b^2)=a(a+b-a+b)/(a^2-b^2)-(2b^2/a^2-b^2)=2b/

【x-3y][x+y]-[x-2y][x +2y]-[x-y

解题思路:根据题意,由整式的运算的知识整理,分析可以求得解题过程:

有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【-

解代数式得:-3x的平方y-2y的三次方因为1/2的平方=-1/2的平方,所以结果仍正确给分吧!嘿嘿!

(x+y)^2(x-y)^2-(x-y)(x+y)(x^2+y^2)分解因式

原式=(x+y)(x-y)[(x+y)(x-y)-(x²+y²)]=(x+y)(x-y)(x²-y²-x²-y²)=-2y²(x+

设数列{X}有界,又有limY=0,证明:limXY=0

因为数列{X}有界,所以设绝对值X

1.[(x-y)^2-2(y -x)]÷(x-y)

1.[(x-y)^2-2(y-x)]÷(x-y)=[(x-y)^2+2(x-y)]÷(x-y)=(x-y)(x-y+2)÷(x-y)=x-y+22.[(3a-7)^2-(a+5)^2]÷(4a-24)