Question

求这两道题的极限

Answer 1

=lim2arctan(1/x)/(1/x)*limsinx/√(1+x²)
=2*0
=0

追答

三角函数非零情况应用夹逼准则
0=-lim1/(e^x+e^-x)≤lim≤lim1/(e^x+e^-x)=0

Answer 2

g.e. = 2*lim(x→+∞)[x*(1/x)]*[sinx/√(1+x²)]
= 2*0 = 0