Question

Does this relation define a function?

y^2=3x
My answer:
3x=y^2|0|3|12|27
y |0|1| 2| 3
y^2=3x is a function because the coordinates I chose are not duplicated.

Answer 1

y^2 = 3 x

y = + sqrt(3x)
BUT
y = - sqrt (3x)

for example if x = 12
y = sqrt(36) = 6
BUT
y = -sqrt(36) = -6
works
so there are two values of y for every x
NOT a function