Question

求极限的问题，过程请详细一点

尤其是有理化的过程，请尽量一步步的来，谢谢

Answer 1

(√(xy+1)-1)/(xy)
= [(√(xy+1)-1)/(xy)] . [(√(xy+1)+1)/(√(xy+1)+1)]
=1/(√(xy+1)+1)
/
lim((x,y)->(0,0) ) xy cos[(√(xy+1)-1)/(xy)]
=lim((x,y)->(0,0) ) xy cos[1/(√(xy+1)+1)]
=0