Question

Which is NOT a function?

A. y = x + 3^2
B. x + y = 3^2
C. x + 3 = y^2
D. y = x^2 - 3

Answer 1

All are functions

Explanation:

A. y = x + 9 A graph of a line. There are no x-values that are the same on the graph. The graph passes the vertical line test.

B. x + y = 9

y = -x + 9 A graph of a line. There are no x values that are the same number on the graph. The graph passes the vertical line test

C. x + 3 = y²

`√(x + 3) = y` The graph passes the vertical line test. On the graph, there are no x-values that are the same number.

D. y = x² - 3 The graph is a parabola. The graph passes the vertical line test (there are no x- values are the same number on the graph).