Functions Question 182

Question: $ \underset{x\to \infty }{\mathop{\lim }},\frac{x^{n}}{e^{x}}=0 $ for

[IIT 1992]

Options:

A) No value of n

B) n is any whole number

C) $ n=0 $ only

D) $ n=2 $ only

Show Answer

Answer:

Correct Answer: B

Solution:

$ \underset{x\to \infty }{\mathop{\lim }},\frac{x^{n}}{e^{x}}=\underset{x\to \infty }{\mathop{\lim }},n\frac{{x^{n-1}}}{e^{x}}=…… $ $ =\underset{x\to \infty }{\mathop{\lim }},\frac{n!}{e^{x}}=\frac{n!}{\infty }=0 $ ,
where n is any whole number $ (,\because n,! $ is defined for all positive integers including zero).