A function is concave if:
Contrast with convex.
A function is convex if:
is an example of a convex function.
Contrast with concave.
The set of points the function is defined for.
A function is injective if it never maps two different inputs to the same output.
See also: surjective, bijective
A function is monotonic if it is non-decreasing or non-increasing.
A function is surjective if, for every possible output, there is one input that produces that output.
See also: injective, bijective