The macOS calculator, on the other hand, has a totally ridiculous bug: it displays "Not a number" for any negative number that you try to take e^x of. 2^x and 1

The macOS calculator, on the other hand, has a totally ridiculous bug: it displays "Not a number" for any negative number that you try to take e^x of. 2^x and 10^x work fine, as does using the x^y button with base e. Typing "e^(-whatever)" on the Spotlight search works, as does e^x of -whatever in the iOS calculator app.