Which of the following functions is quadratic?

f (x) = 5^2

f (x) = 3 (x-4) (x+3)

f (x) = 2/3

f (x) = 2x^3+3x^2-5

f (x) = 3 (x-4) (x+3)

Step-by-step explanation:

Quadratic function follows the f (x) = ax^2 + bx+c pattern

f (x) = 3 (x-4) (x+3) after multiplying out is equal to

f (x) = (3x-12) (x+3) = (3x^2+9x-12x-36) = (3x^2-3x-36)

f (x) = (3x^2-3x-36)

where

a = 3

b = - 3

c = - 36