In the real world, what might be a situation where it is prefer for the data to form a relation but not a func

Question

Function

Answer 1

Consider the set P of all people in the world. A person can have several siblings. Id we say a R b if b is a sibling of a, then we set up a sibling relation R from P to P. It's sure a treal world relation and it's not a function, because a person can have several siblings. If a has 2 siblings, b1 and b2, then tyhe paisr (a,b1) and (a, b2) are both in R. Not afunction.

Another example, consider the points inside an open circle of radius R. Then, for every point (x,y) in this circle we have x^2 = y^2 =1. This defines a reçlation but not a function, because for each x in (-R, R) there corresponds 2 values for y.

Answer 2

how about a hashing algorithim. It will not be one to one or necessary onto. This will allow the hashing algorithim run faster