Page 63 - Calculus Demystified

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Fig. 1.58 CHAPTER 1 Basics

Fig. 1.59

Math Note: In mathematics, we commonly write log x to mean the natural log-
arithm. Thus you will sometimes encounter ln x and sometimes encounter log x
(without any subscript); they are both understood to mean log x, the natural
e
logarithm.

The exponential function exp x is defined to be the inverse function to ln x.
x
Figure 1.59 shows the graph of y = exp x. In fact we will see later that exp x = e .
x
More generally, the function a is the inverse function to log x. The exponential
a
has these properties:
b
c
(a) a b+c = a · a ;