Definition:Cotangent/Real Function

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

The real function $\cot x$ is defined as:

$\cot x = \dfrac {\cos x} {\sin x} = \dfrac 1 {\tan x}$


$\sin x$ 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 $\sin x \ne 0$.