Which function has a vertex at the origin?

f(x) = (x + 4)2

f(x) = x(x – 4)

f(x) = (x – 4)(x + 4)

f(x) = –x2

Which function has a vertex at the origin?

f(x) = (x + 4)2

f(x) = x(x – 4)

f(x) = (x – 4)(x + 4)

f(x) = –x2