lim(x=>0,y=>0) (x+y)/(x-y)=?
(lim) x/x-y=
数学题 (lim)X→0 Y→0 x/(x-y)=?
lim(x+y)ln(x^2+y^2)=?(x,y)-(0,0) 谁帮忙做下.
证明lim(x,y)→(0,0),xy/根号(x²+y²)=0
y=lim (x → 0) ( √1+xsinx - √cosx) / arcsin^2x.y=lim (n → ∞)
以下两个极限怎么算一、f(x,y)={xy/(x^2+y^2) (x,y)≠(0,0)0 (x,y)=(0,0)}lim
求两道多元函数的极限lim=(x²-y²-2x+2y)/(x+ y-2) ① (x,y)→(2,0)
跪求极限Y=lim (xy+1)/x^4+y^4,当(x,y)→(0,0),
高数:x→0,y→2lim[ln(x+e^xy)/x]=?
x>=0,y
设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y
lim sin(y×x^2+y^4)/(x^2+y^2) x,y都趋于0,