Use the Quotient Rule and Exercise 88 to show that d/dx (e^kx) = ke^kx, for negative integers k.

Data from exercise 88

Proof by induction is a method in which one begins by showing that a statement, which involves positive integers, is true for a particular value (usually k = 1). In the second step, the statement is assumed to be true for k = n, and the statement is proved for k = n + 1, which concludes the proof.