How do you use the horizontal line test to determine whether the function g(x)=10g(x)=10 is one to one?

1 Answer
May 31, 2017

See explanation.

Explanation:

A graph of a one to one function cuts any horizontal line in at most one point (zero or one).

If there is a horizontal line y=ay=a which has more than one points common with the graph, then the function is not one to one (value aa is assigned to more than one argument)

The function given as the example in this question is a constant one (i.e. it has the same value 1010 for all real numbers). So this value is given to more than one point. The line y=10y=10 has infinitely many points common to the function's graph.