Definition, Meaning & Synonyms

cos

Mathematical function
/kɒs/
Definition
The cosine of an angle in a right triangle is the ratio of the length of the adjacent side to the length of the hypotenuse.
Examples
  • The cosine of 0 degrees is 1.
  • In a right triangle, if one angle is 30 degrees, the cosine of that angle is √3/2.
  • Calculating the cos of an angle can help find the lengths of sides in trigonometric problems.
Meaning
In trigonometry, ‘cos’ refers to a basic function that is used to relate the angles of a triangle to the lengths of its sides.
Synonyms
  • Cosine