In math, 'e' isn't just a letter, it's an irrational number! This tutorial shows you how mathematicians use the letter 'e' to represent a specific value and how having a base of 'e' is called a natural base.

Keywords:

definition

natural base

e

natural log

logarithm

Background Tutorials

Know that numbers that are not rational are called irrational. Understand informally that every number has a decimal expansion; for rational numbers show that the decimal expansion repeats eventually, and convert a decimal expansion which repeats eventually into a rational number.

Is an irrational number just a way to describe a number that's lost its mind? Not really. :) An irrational number is simply a number that cannot be written as a fraction. Check out the definition, learn an important property of these special numbers, and take a look at some examples of irrational numbers.

Graph exponential and logarithmic functions, showing intercepts and end behavior, and trigonometric functions, showing period, midline, and amplitude.