对x平分y平方/x平方 y平方求微分
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x/y=3x=3y(x^2+y^2-xy)/(x^2-y^2)=(9y^2+y^2-3y^2)/(9y^2-y^2)=7y^2/8y^2=7/8
两个y²?应该是(2x+y)(4x²-2xy+y²)=2x(4x²-2xy+y²)+y(4x²-2xy+y²)=8x³-
(x平方-y平方)/(x+y)+(x平方-2xy+y平方)/(x-y)=(x+y)(x-y)/(x+y)+(x-y)^2/(x-y)=x-y+x-y=2(x-y)
是假命题,因为,x^2y
x^2+y^2=6y-4x-13x^2+4x+4+y^2-6y+9=0(x+2)^2+(y-3)^2=0x=-2y=3x^2-y^2=(-2)^2-3^2=4-9=-5
(x平方+y平方)平方-y平方=x平方+6所以(x²+y²)²-(x²+y²)-6=0(x²+y²+2)(x²+y
∵/x+y-7/(绝对值)+(xy-5)平方=0∴x+y-7=0xy-5=0∴x+y=7xy=5∴x²+y²=(x+y)²-2xy=7²-2×5=39
y=2x/3则xy=2x2/3y2=4x2/9所以原式=(2x2/3)/(x2+4x2/9)-(4x2/9)/(x2-4x2/9)=(2/3)/(1+4/9)-(4/9)/(1-4/9)=6/13+4
因为x²+y²-4x+2y+5=0所以(x²-4x+4)+(y²+2y+1)=0所以(x-2)²+(y+1)²=o所以x=2y=-1所以下面
不等于再问:那应该?再问:再答:好像分解不了了………再答:楼主在?再问:在呢再答:再答:直接成这样再答:用平方差公式再问:我刚刚也做出来了再问:对呢再答:采纳下再问:再问:是这样的再答:不是呀再答:再
=x^3-y^3-(x^3+y^3)=-2y^3^3表示三次方
x²y(x-y)-xy²(x-y)=xy(x-y)(x-y)=xy(x-y)²如果不懂,祝学习愉快!
将xy=8代入x平方y-8xy平方-x+y=56得8x-8y-x+y=56x-y=8x平方+y平方=(x-y)^2+2xy=8^2+2*8=64+16=80
x{x-1}-{x^2-y}=-3即x^2-x-x^2+y=-3-x+y=-3x-y=3而x^2+y^2-2xy=(x-y)^2=3^2=9
x平方-y平方=4(x+y)(x-y)=4(x+y)平方*(x-y)平方=4*4=16
考点:换元法解一元二次方程分析:设x2+y2=m,化简方程后求得m的值即可.设x2+y2=m,方程化为(m+2)(m-1)=0∴m1=-2,m2=1∵x2+y2≥0∴m1=-2舍去,即x2+y2=1.
=(x²+y²)²-(2xy)²=(x²+2xy+y²)(x²-2xy+y²)=(x+y)²(x-y)
根据:a²-b²=(a+b)(a-b)(x²+y²)²-(2xy)²假设:(x²+y²)²=a²,(
(x²-y²)/(x-y)²=(x+y)(x-y)/(x-y)²=(x+y)/(x-y)
∵(2y平方+三分之四x平方+3xy-3x)-三分之一(9xy+6y平方+x平方)=2y²+4x²/3+3xy-3x-3xy-2y²-x²/3=x²-