Error with exponential fractions

[Han]

(11-12-2014 01:03 AM)Thomas Klemm Wrote:  

(11-11-2014 11:59 PM)Han Wrote:  Indeed, this is what the HP Prime is showing -- except it is missing a pair of necessary outer parentheses.

That's not what the HP Prime is showing. Simply put: it shows a wrong result.
Exponentiation is right associative:
\[\frac{1}{e^{t^2}}=\frac{1}{e^{(t^2)}}\]

If you type:

\[ simplify\left(\frac{e^{-x}}{e^{x}}\right) \]

and then follow up with:

\[ Ans - \frac{1}{e^{2x}} \]

and then use the simplify menu option, you get the correct result 0. In other words, the HP Prime is calculating it correctly, but displaying it incorrectly due to a missing set of parentheses. I was not suggesting that what it was displaying was correct and simply noting that
\[ \frac{1}{e^{x^2}} \text{ looks like the correct expression} \frac{1}{(e^x)^2} \]
but lacking the the necessary parentheses.