Question

Which of the following does not represent a function?

a. graph of positive parabola oriented about the y axis with y intercept at negative 6
b. graph of a line with negative slope through the origin
c. graph of an absolute value function
d. graph of a parabola symmetric about the x axis with x intercept at negative 5

Answer 1

d. it does not pass the vertical line test

Answer 2

The following which does not represent a function is:

d. graph of a parabola symmetric about the x axis with x intercept at negative 5.

Explanation:

Function--

A relation is said to be a function if there is only one image corresponding to each element i.e. no element has two images.

i.e. by the graph we may check the graph is a function if it passes the vertical line test i.e. any line passing through the domain and parallel to the x-axis should intersect the graph exactly once.

Any parabola with symmetry as x-axis will not be a function.

It fails the vertical line test.

( since there will be two images corresponding to some x and such could be seen with the help of a graph)