lim [tan(π/4+2/n)]^n =e^[lim n*lntan(π/4+2/n)]=
n→∞ n→∞
e^[lim lntan(π/4+2/n)/(1/n)]("0/0"型,利用罗必塔法则)
n→∞
=e^[lim cot(π/4+2/n)*sec^2(π/4+2/n)*(-2/n^2)/(-1/n^2)]=e^(1*2*2)=e^4
n→∞
lim [tan(π/4+2/n)]^n =e^[lim n*lntan(π/4+2/n)]=
n→∞ n→∞
e^[lim lntan(π/4+2/n)/(1/n)]("0/0"型,利用罗必塔法则)
n→∞
=e^[lim cot(π/4+2/n)*sec^2(π/4+2/n)*(-2/n^2)/(-1/n^2)]=e^(1*2*2)=e^4
n→∞