Question: can e be raised to a negative power?
Answer: To start, your answer is e^(-x) or exp(-x) is equal to 1/(e^x) or 1/exp(x). ... In our case, this means, (1/x)^k, where the exponent can be brought inside the parentheses to make (1^k)/(x^k), and since 1^k = 1, it is just 1/(x^k).