Question

大家看看有什么区别lim lim [(x^2-y^2)/(x^2+y^2)]y-0 x-0lim lim [(x^2-y

Answer 1

待求 函数在(0,0)点是不连续的

(1)lim [(x^2-y^2)/(x^2+y^2)] =lim(-y^2)/(y^2)=-1

x-0

lim lim [(x^2-y^2)/(x^2+y^2)] = -1

y-0 x-0

(2)lim [(x^2-y^2)/(x^2+y^2)] =lim(x^2)/(x^2)=1

y-0

lim lim [(x^2-y^2)/(x^2+y^2)] = 1

y-0 x-0