lim x^2y^2/x^2y^2+(x-y)^2 这个题的极限怎么求呢..lim x^2y^2/x^2y^2+(x-y)^2(x,y)-(0,0)怎么求极限哦..

lim sin(y×x^2+y^4)/(x^2+y^2) x,y都趋于0， x.y都趋于正无穷大时：lim（x^2+y^2)e^-(x+y)? lim(x→∞,y→∞) x+y/x^2-xy+y^2 极限x,y趋向0 lim x y/(x^2+y^2) =( ). 求极限lim(x→+∞,y→+∞) (X+Y)/(X^2-Y^2) lim(x→∞,y→∞) x+y/x^2-xy+y^2 lim((x^2)y)/(x^4+y^2),x和y都趋向于0 lim(x+y)cos(1/(x^2+y^2))且x,y趋于0 lim(x→0y→1)(1+xe^y)^(2y+x/x)求极限 证明 lim（2x-y）/（x+y） 不存在(x,y)趋于(0,0) lim(x,y)趋向于(无穷,a) (1+1/x)^(x^2/(x+y))answer:e lim(x→+∞,y→0) (1+1/x)^(x^2/(x+y)) lim(x,y)->(∞,a)(1-1/x)^（x^2/x+y） lim(x,y)->(0,2)(1-3xy)^2/x 1.lim(2x-sinx)/(2x+sinx) (x→0)2.lim(sinsinx)/x (x→0)3.lim 4/y (y→∞) (lim) x/(x-y) 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