- #1
Tspirit
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Homework Statement
In the Griffiths book <Introduction to QM>, Section 2.3.2: Analytic method (for The harmonic oscillator), there is an equation (##\xi## is very large)
$$h(\xi)\approx C\sum\frac{1}{(j/2)!}\xi^{j}\approx C\sum\frac{1}{(j)!}\xi^{2j}\approx Ce^{\xi^{2}}.$$
How to understand the meaning of the third approximately equal sign?
Homework Equations
I know the Taylor series
$$e^{x}=\frac{x^{n}}{n!}$$
The Attempt at a Solution
If take place of ##\xi## with ##2\xi##, the equation may hold. However, can it be like this? What is the series of ##e^{\xi^{2}}## in real? I don't want the approximation. Thank you.