Circular function and Single-valued function

Circular function noun - Function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle.

Single-valued function and circular function are semantically related. In some cases you can use "Single-valued function" instead a noun phrase "Circular function".

Single-valued function noun - Mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function.

Circular function and single-valued function are semantically related. Sometimes you can replace phrase "Circular function" with "Single-valued function", this phrases are similar.