In which of the following equations is y a function of x? and why?

Question

a) 3x+2y-7 = 0

b) 5(x^2)y = 9-2x

c) 3x^2 - 4y^2 = 9

d) x = 3y^2 -1

e) none of the above

Answer 1

a) 3x+2y-7 = 0

b) 5(x^2)y = 9-2x

c) 3x^2 - 4y^2 = 9

d) x = 3y^2 -1

Y is an implicit function of X in all of them, and each equation can be (I think) rewritten into that form.

But as stated, none of these are in the form of an explicit y = f(x).

so I'd go for (e)

.

Answer 2

e)

y as a function of x is written as y=.........

Although all the equations a-d can be written in the form y=f(x), none of them are in that form.