Respuesta :

znk

Answer:

y = -x²  

Step-by-step explanation:

The simplest quadratic I can think of is

y = -x²

It must have a maximum because as

x ⟶  -∞, y ⟶ -∞ and as

x ⟶ +∞, y ⟶ -∞.

There must be a maximum somewhere between the two extremes.