Which of the following is a function?
A) -x^2 + 2y^2 - 4 = 36
B) {(6, -5), (-1, -5), (-4, -5)}
C) {(-5, -4), (-5, -3), (-3, 6)}
D) x = y^2 - 3
apply the definition of a function to each and see if it fits.
e.g. in C ---> (-5,-4) and (-5(-3)
two different values of y for the same x value, not a function