\begin{definition}[Definition:Cotangent/Real Function]
Let $x \in \R$ be a real number.
The real function $\cot x$ is defined as:
:$\cot x = \dfrac {\cos x} {\sin x} = \dfrac 1 {\tan x}$
where:
: $\sin x$ is the sine of $x$
: $\cos x$ is the cosine of $x$
: $\tan x$ is the tangent of $x$
The definition is valid for all $x \in \R$ such that $\sin x \ne 0$.
Category:Definitions/Cotangent Function
\end{definition}