Answer to Question #349859 in Discrete Mathematics for mengal

Question

Is function f defined by f = {(1, 2), (3, 4), (5, 6), (8, 6), (10, -1)}, a one to one function?

Answer 1

The function is one to one when for every value of $x$ there is a unique value of $f(x).$

But we have two points (5, 6) and (8, 6) with the same output 6: $f(5)=6$ and $f(8)=6.$

So $f$ isn't a one to one function.

Answer: $f$ isn't a one to one function.