lim(xy/(x^2+y^2))^x^2 x,y趋近无穷 求极限

lim(x,y)->(0,2)(1-3xy)^2/x 求极限lim(x,y)→(+∞,+∞) [(xy)/(x^2+y^2)]^xy.求极限lim(x,y)→(+∞,+∞) [(xy)/(x^2+y^2)]^xy, lim(x→∞,y→∞) x+y/x^2-xy+y^2 lim(x→∞,y→∞) x+y/x^2-xy+y^2 求极限：lim (x^2+y^2)^xy（x,y）lim (x^2+y^2)^xy x,y→0 这个极限是多少啊!怎么算? lim(xy/(x^2+y^2))^x^2 x,y趋近无穷 求极限 求极限lim(x,y)→(+∞,+∞) (xy/(x^2+y^2))^x^2 求极限. lim (x→0) [√ (xy+4) -2 ]/xy (y→0)lim (x→0)(y→0)[√ (xy+4) -2 ]/xy 高数：x→0,y→2lim[ln(x+e^xy)/x]=? 求极限lim(xy)^2/(x^2+y^2)^2,(x,y)趋于（0,0） 极限x趋于2 y趋于o lim 1-xy/x^2+y^2 = 求下列各极限 lim(x,y)→(0,1) (2-xy)/(x^2+2y) 证明：lim(x,y)→(0,0)xy/x^2+y^2极限不存在 求极限 lim((x,y）→（0,0)) (x^2+y^2)sin1/xy 求lim(x,y)~(0,1)1-xy/x^2+y^2的极限,要详解 lim(x,y)趋近于(0,0)(xy^2-sinxy^2)/(x^3*y^6)= 求极限lim(x→1 y→2) (x²+y²)/xy x→2,y→0,求lim sin[(8 -x)y]/xy=多少呀?