Definition:Power (Algebra)/Integer

Definition
Let $x \in \R$ be a real number.

Let $n \in \Z$ be an integer.

The expression $x^n$ is called $x$ to the power of $n$.

$x^n$ is defined recursively as:


 * $x^n = \begin{cases}

1 & : n = 0 \\ x \times x^{n-1} & : n > 0 \\ \dfrac 1 {x^{-n}} & : n < 0 \end{cases}$

Also known as
The expression $x^n$ is vocalised in a number of other ways:
 * the $n$th power of $x$
 * $x$ to the $n$th power
 * $x$ to the $n$th
 * $x$ to the $n$.

Also see

 * Power of Zero for the definition of $x^n$ where $x = 0$.


 * Multiplicative Group of Real Numbers, where it is shown that the real numbers form a group under multiplication.


 * Power of an Element in a Group, where the operation is defined in a general group and shown to be consistent with the definition given here.