Is $(e^\pi-\pi^e)$ positive or negative? why?
Asked
Active
Viewed 170 times
1 Answers
1
If $a>b\geq e$, then $a^b<b^a$. It follows from the fact that the function $$ f(x)=\frac{\log x}{x} $$ is decreasing over $I=(e,+\infty)$, since: $$ f'(x) = \frac{1-\log x}{x^2} $$ is negative over $I$.

Jack D'Aurizio
- 353,855
-
thanks. was helpful for me – Alireza Feb 07 '15 at 20:47
-
Shouldn't it be $a > b \geq e$ in order to apply this to the actual question? – rubik Feb 07 '15 at 20:52
-
@rubik: yes, you're right. Now fixed. – Jack D'Aurizio Feb 07 '15 at 20:56