- #1
ehrenfest
- 2,020
- 1
Homework Statement
For which real numbers c is [tex](e^x+e^{-x})/2 \leq e^{cx^2}[/tex] for all real x?
Homework Equations
The Attempt at a Solution
I think you can expand both sides into series and term by term compare them. The left side is
[tex]\sum_{n=0}^{\infty}\frac{x^{2n}}{2n!}[/tex]
Can someone help me with the right side?