Discrete Math Onto Function

A function is said to be one to one if every y value has exactly one x value mapped onto it and many to one if there are y values that have more than one x value mapped onto them.

Discrete math onto function. I m confused on what exactly onto means and how its different from the definition of a function. This means that for any y in b there exists some x in a such that y f x. For all elements x1 x2 a. Http bit ly 1zbplvm subscribe on youtube.

A b is said to be one to one if. In discrete math we can still use any of these to describe functions but we can also be more specific since we are primarily concerned with functions that have n or a finite subset of n as their domain. F x y. Please see the updated video at https youtu be plszgywo ew the full playlist for discrete math i rosen discrete mathematics and its applications 7e can.

F x1 f x2 x1 x2. F 1 y x x. Is onto the one that means each x is mapped to only 1 y. A function that is not one to one is referred to as many to one.

That is f 1 y x x f x y. If the function were onto it would mean that each value of n would be at the receiving end of the mapping. We say that f 1 y f 1 y is the complete inverse image of y y under f. How to write them the terminology and how to compose them.

Inverse functions only exist for bijections but f 1 y f 1 y is defined for any function f. This function maps ordered pairs to a single real numbers. Take any real number x in mathbb. Equivalently for every b b there exists some a a such that f a b.

Describing a function graphically usually means drawing the graph of the function. The image of an ordered pair is the average of the two coordinates of the ordered pair. F 1 y f 1 y is not an inverse function. A b is surjective onto if the image of f equals its range.

Is this function onto. But with f n n 1.