Question and Answers Forum

All Questions      Topic List

Arithmetic Questions

Previous in All Question      Next in All Question      

Previous in Arithmetic      Next in Arithmetic      

Question Number 41855 by 123456780 last updated on 14/Aug/18

lim_(x→+∞  ) ((n!)/(ln (1+n!)))  find the limit

$$\underset{{x}\rightarrow+\infty\:\:} {\mathrm{lim}}\frac{\mathrm{n}!}{\mathrm{ln}\:\left(\mathrm{1}+\mathrm{n}!\right)} \\ $$$$\mathrm{find}\:\mathrm{the}\:\mathrm{limit} \\ $$

Commented by prof Abdo imad last updated on 14/Aug/18

let put p=n! ⇒  ((n!)/(ln(1+n!))) =(p/(ln(1+p)))  =(p/(lnp +ln(1+(1/p))))  ∼ (p/(lnp +(1/p))) ∼ (p/(ln(p))) (p→+∞)  but lim_(p→+∞) (p/(ln(p))) =+∞ ⇒  lim_(n→+∞)   ((n!)/(ln(1+n!))) =+∞

$${let}\:{put}\:{p}={n}!\:\Rightarrow\:\:\frac{{n}!}{{ln}\left(\mathrm{1}+{n}!\right)}\:=\frac{{p}}{{ln}\left(\mathrm{1}+{p}\right)} \\ $$$$=\frac{{p}}{{lnp}\:+{ln}\left(\mathrm{1}+\frac{\mathrm{1}}{{p}}\right)}\:\:\sim\:\frac{{p}}{{lnp}\:+\frac{\mathrm{1}}{{p}}}\:\sim\:\frac{{p}}{{ln}\left({p}\right)}\:\left({p}\rightarrow+\infty\right) \\ $$$${but}\:{lim}_{{p}\rightarrow+\infty} \frac{{p}}{{ln}\left({p}\right)}\:=+\infty\:\Rightarrow \\ $$$${lim}_{{n}\rightarrow+\infty} \:\:\frac{{n}!}{{ln}\left(\mathrm{1}+{n}!\right)}\:=+\infty \\ $$$$ \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com