Exponential Notation

Concept sheet | Mathematics

The Components of Exponential Notation

Definition

​​Exponentiation is an operation which consists of raising a base to an exponent.
||\text{base}^\text{exponent} = \text{power}||The result of an exponentiation is a power.

In practical terms, exponential notation is composed of the following:

Example

||\begin{align} &&&&& \color{red}{\text{base}} && = && \color{red}{4} \\ \color{red}{4}^\color{blue}{3}&= \color{magenta}{64} &&\large\Rightarrow && \color{blue}{\text{exponent}} && = && \color{blue}{3} \\ &&&&& \color{magenta}{\text{power}} && = && \color{magenta}{64} \end{align}||  ​

Reading Exponential Notation

Generally, there are two ways to read exponential notation. 

124

1st way

2nd way

"12 to the 4th power"

"12 to the power of 4"

Depending on the value of the exponent, more precise terms can be used.

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Exponent 2
When a number is raised to the exponent |2,| the term "square" is used. For example, |5^2| usually reads |5| squared. For this reason, the power |(25)| is called a square number.

​Exponent 3
When a number is raised to the exponent |3,| the term "cube" is used. For example, |5^3| usually reads |5| cubed. For this reason the power |(125)| is called a cubic number.

The Definition of an Exponent

Definition

Exponential notation is a way to express a number as a power |a^b,| where |a| is called the base and |b,| the exponent.

The exponent corresponds to the number of times that we multiply the base by itself.

||a^n=\underbrace{a\times a\times \ldots\times a\times a}_{n\text{ times}}||

In other words, exponentiation is a series of multiplications by the same number.​ 

Example

||\begin{align} 4^3 &= \underbrace{4 \times 4 \times 4}_{3 \ \text{times}} \\ &=64 \end{align}|| ​

Moreover, the number of times this number appears in the series of multiplications is directly related to the value of the exponent.

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Image

Therefore, each time the exponent increases by |1,| the previous power must be multiplied by the value of the base, in this example, by |4.|