一道二元函数求极限的题征求解答若x→0,y→0lim(x+y)sin〔1/(x^2+y^2)〕的极限.

问题描述:

一道二元函数求极限的题征求解答
若x→0,y→0
lim(x+y)sin〔1/(x^2+y^2)〕的极限.

lim(x->0,y->0)(x+y)sin(1/(x^2+y^2)
lim(x->0,y->0)(x+y)=0
|sin(1/(x^2+y^2)|0,y->0)(x+y)sin(1/(x^2+y^2)
=0