Question

15. Which of the following relations defines y as a function of x?

Answer 1

Remember that

The data set is a function if every element of the domain corresponds to exactly one element of the range

so

Verify each option

I ------> is a function (every element of the domain corresponds to exactly one element of the range)

II -----> is not a function (every element of the domain does not correspond to exactly one element of the range)

III ---> is a function (every element of the domain corresponds to exactly one element of the range)

IV ----> is not a function (every element of the domain does not correspond to exactly one element of the range)

therefore

The answer is

Both I and III define a y as function of x