Question

for which of these equations is y a function of x
A) y=3x^2
B)xy=1
c)y^2=x
D) y^3=8x

Answer 1

The 1st , 2nd and the 4th !
Because, for all value of x, there is only one correspond value of y.
remark that in the 4th we have :
\[y^3=8x\]
so ;
\[y=2\sqrt[3]x\]

Answer 2

well which of those depends on x :)