Question

What is the derivative of `y=e^(-1)`?

Answer 1

y = `e^(-1)` is a constant function.
See, `e^(-1) = 1/e` and there's no x in the expression.

The derivative of any constant is zero.

So `dy/dx = 0.`

Unless… the letter e has been defined as a variable, and the question is to find `dy/(de).` Then the derivative would be `-1/(e^2)`. But that seems unlikely.

\dansmath to the rescue!/