Question

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

Answer 1

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=a` which has more than one points common with the graph, then the function is not one to one (value `a` 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 `10` for all real numbers). So this value is given to more than one point. The line `y=10` has infinitely many points common to the function's graph.