Marlene's Trigonometry Calculator Trigonometric Functions   
Site Last Updated 04/06/2009
Please report any errors/suggestions to
the email address at bottom of the page

Trigonometric Functions

This page will define and explain the trigonometric functions.



The Trigonometric Functions are:

Name Abbreviation
sine sin
cosine cos
tangent tan
cotangent cot
secant sec
cosecant csc


The function values depend on the measure of the angle.

The functions are defined:

      sine Ω  =  (side opposite Ω)/hypotenuse
      cosine Ω  =  (side adjacent Ω)/hypotenuse
      tangent Ω  =  (side opposite Ω)/(side adjacent Ω)
      cotangent Ω  =  (side adjacent Ω)/(side opposite Ω)
      secant Ω  =  hypotenuse/(side adjacent Ω)
      cosecant Ω  =  hypotenuse/(side opposite Ω)

Where Ω is an acute angle (an angle < 90°): θ or ß on the figure below.


Example:

      sine θ  =  y/h       sine ß  =  x/h
      cosine θ  =  x/h       cosine ß  =  y/h
      tangent θ  =  y/x       tangent ß  =  x/y
      cotangent θ  =  x/y       cotangent ß  =  y/x
      secant θ  =  h/x       secant ß  =  h/y
      cosecant θ  =  h/y       cosecant ß  =  h/x