limtan(xy)y-热点-考试作业题

xy'=y+xy的

xy'=y+xy的xdy=(y+xy)dxdy/y=((1+x)/x)dxln|y|=ln|x|+x+cy=±e^(ln|x|+x+c)其中c是常数

|x|/x+y/|y|+xy/|xy|=由题可知x,y都不等于0.下面分x>0,y>0x>0yx0x四种情况去绝对值,这样就得到你要的答案啦.我复制楼下的结果来的,这是正确的.当x>0；y>0时,|x|/x+y/|y|+xy/|xy|=1+

【x(xy-xy)-y(x-xy)】÷3xy2xy

-x-3xy+y

-x-3xy+y-(x2+3xy-y2)=-（x2+3xy+2.25y2-3.25y2）=-（(x+1.5)2-3.25y2）结束了？不会分解分解肯定不对你们老师出的题？对啊题出错了？有人分解出来了？全部展开-(x2+3xy-y2)收起

xy-1+x-y

xy-1+x-yxy-1+x-y=XY+X-Y-1(加法交换律）=（XY+X）－（Y＋1）＝X（Y＋1）－(Y+1)（提取公因式X）=(Y+1)(X-1)（提取公因式Y+1）这样可以么?原式=x-1+y(x-1)=（x-1）(y+1)xy-

集合{(x,y)|xy

集合{(x,y)|xy不对,还有两条轴上也有成立

计算：(xy-x²)×x-y/xy这题少括号了吧.

XY（XY-X2)乘以------------X-YXY(XY-X^2)(X-Y)=X^2Y(X-Y)(X-Y)=(X-Y)(X^2Y-1)

4xy平方-4xy-y立方

4xy平方-4xy-y立方4xy平方-4xy-y立方=4xy²-4xy-y³=y(4xy-4x-y²)

x^2-xy/xy-y^2约分

(xy+1)(x+1)(y+1)+xy

(xy+1)(x+1)(y+1)+xy(xy+1)(x+1)(y+1)+xy=(xy+1)(xy+1+x+y)+xy=(xy+1)(xy+x+1)+y(xy+1)+xy=(xy+1)(xy+x+1)+y(xy+1+x)=(xy+x+1)(x

xy^2-2xy+2y-4

xy^2-2xy+2y-4xy(y-2)+2(y-2)下步不写了能看懂吧?

【xy-x²】*xy/x-y

【xy-x²】*xy/x-y解(xy-x²)xy/(x-y)=x²y(y-x)/[-(y-x)]=-x²y

xy^2-2xy+2y-4

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

对xy求导,为什么等于y+xy'这是求导法则,要证明要用到极限去证明才行,一两句话说不清楚为什么?公式是这样的：[f（x）g（x）]'=f'（x）g（x）+f（x）g'（x）记得就行了.

XY+Y=YX问：XY是多少89

(xy+1)(x+1)(y+1)+xy

(xy+1)(x+1)(y+1)+xy是(xy+1)(x+1)(y+1)+xy=(xy+1)[(xy+1)+(x+y)]+xy=(xy+1)^2+(x+y)(xy+1)+xy=(xy+1+x)(xy+1+y)

xy'+y=-xy^2的通解

xy'+y=-xy^2的通解y'为一次导?xy'/y^2+1/y=-x-x(1/y)'+1/y=-x1/y=t-xt'+t=-x(t'x-t)/x^2=1/x(t/x)'=1/xt/x=lnx+ct=xlnx+cx1/y=xlnx+cxy=

(2xy-y)-2xy化简

(2xy-y)-2xy化简=2xy-y-2xy=-y

化简4xy-y-xy+x

化简4xy-y-xy+x原式=3xy+x-y答案是3xy+x-y，此类题只需将相同字母前的系数相加减，统称合并同类项，望采纳3xy+x-y原式=3Xy+x-y