page 1 of 2
e is a number that can be defined in many ways. First,
|e = 1+|
Also, e is the number such that
The numerical value of e is approximately 2.71828.... The function f (x) = e x is an exponential function, which is a function of the form f (x) = a x , where a is a positive constant. The graph of f (x) = e x is shown below.
The inverse of the function e x is the natural log function ln(x) . These two graphs are pictured below:
Recall that if log a b = x , then x is the power that a must be raised to in order to equal b .
With the natural log, the base is e . So, for example, ln(e) = 1 . Because e x and ln(x) are inverses, the following relations hold:
Take a Study Break!