\sum_(n=1)^(\infty ) (n!)/(5^(n))

asked by guest
on Jan 19, 2025 at 3:22 pm



You asked:

Evaluate the expression: \(\sum_{n = 1}^{\infty} {\frac{n!}{{5}^{n}}}\)

MathBot Answer:

The infinite series \(\displaystyle\sum_{n=1}^{\infty} \frac{n!}{5^{n}}\) diverges.


We can use the nth-term test to determine convergence of this series.

Given a series \(\displaystyle\sum a_n\), if \(\displaystyle\lim_{n \to \infty}a_n \neq 0\) or does not exist, then the series diverges.
This test cannot prove convergence.

\(\displaystyle\lim_{n \to \infty} 5^{- n} n!\) does not exist.

Therefore the series diverges.