Answer to Question #193972 in Discrete Mathematics for Diganta Saha

Question

Apply your knowledge gaining from this course in describing how you convert a function into a relation and a relation into a function?

Answer 1

If we have a function $f: X\to Y$, then define a relation $R\subset X\times Y$ in the following way: $R=\{(x,y)\ |\ y=f(x) \}\subset X\times Y.$

On the other hand, for a functional relation $R\subset X\times Y$ let us define a function $f: X\to Y$

in the following way: $y=f(x)$ if and only if $(x,y)\in R.$