trigonometric function

Angol

trigonometric function (tsz. trigonometric functions)

Function	Abbreviation	Description	Identities (using radians)
sine	sin	opposite/hypotenuse	$\sin \theta =\cos \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\csc \theta }}$
cosine	cos	adjacent/hypotenuse	$\cos \theta =\sin \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\sec \theta }}\,$
tangent	tan (or tg)	opposite/adjacent	$\tan \theta ={\frac {\sin \theta }{\cos \theta }}=\cot \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\cot \theta }}$
cotangent	cot (or cotan or cotg or ctg or ctn)	adjacent/opposite	$\cot \theta ={\frac {\cos \theta }{\sin \theta }}=\tan \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\tan \theta }}$
secant	sec	hypotenuse/adjacent	$\sec \theta =\csc \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\cos \theta }}$
cosecant	csc (or cosec)	hypotenuse/opposite	$\csc \theta =\sec \left({\frac {\pi }{2}}-\theta \right)={\frac {1}{\sin \theta }}$