Definition:Negative Real Function

Definition
Let $I$ be a real interval.

Let $f$ be a real function.

Then $f$ is negative (on $I$) iff:
 * $\forall x \in I: f \left({x}\right) \le 0$

Also known as
A negative real function is also described as non-positive in order to avoid confusing with a strictly negative real function.

Also see

 * Definition:Strictly Negative Real Function


 * Definition:Positive Real Function
 * Definition:Strictly Positive Real Function