lim _(xarrow 0),dfrac (xy)({x)^2+(y)^2}=

lim _(xarrow y)dfrac (1-xy)({x)^2+(y)^2}-|||-bigcirc (3) lim 1-√(xy+1)-|||-y)→(0

lim _(xarrow 0)dfrac (sin (x{y)^2)}({y)^2}=______.=______.

[题目]已知函数f(x,y)在点(0,0)的某个邻域内连-|||-续,且 lim _(xarrow 0)dfrac (f(x,y)-xy)({({x)^2+(y

已知函数 z=f(x,y) 连续且满足 lim _(xarrow 1)dfrac (f(x,y)-x+2y+2)(sqrt {{(x-1))^2+(y)^2}}

6.求下列各极限:-|||-(1) lim _((x,y)arrow (0,1))dfrac (1-xy)({x)^2+(y)^2} :-|||-(3) lim

6.求下列各极限:-|||-(1) lim _((x,y)arrow (0,1))dfrac (1-xy)({x)^2+(y)^2} ;-|||-(3) lim

3.单选题-|||-二元函数极限 lim _(xarrow 0)(dfrac (1-cos sqrt {{x)^2+(y)^2}}({e)^2+(y)^2-1}

2.lim _(xarrow 0)(dfrac (2+{e)^dfrac (1{x)}}(1+{e)^dfrac (4{x)}}+dfrac (sin x)(|

lim _(xarrow 0)dfrac (sqrt {3xy+4)-2}(xy)= __

函数f(x,y)= dfrac (xy)({x)^2+(y)^2},(x)^2+(y)^2neq 0-|||-0, ^2+(y)^2=0在点（0，0）处（）。