What is the maximum and minimum values of a Quadratic expression

An expression of the type ax2+bx+c is called " quadratic expression".

The quadratic expression ax2+bx+c takes different values as x takes different values.

As x varies from -`prop` to + `prop`ax2+bx+c

has a minimum value whenever a> 0.
The minimum value of the quadratic expression is (4ac-b2 )/4a and it occurs at x = - b/2a.

2. has a maximum value whenever a< 0.

The maximum value of the quadratic expression is (4ac-b2 )/4a and it occurs at x = - b/2a.

Max and min in a quadratric equation are referring to y values. The graph looks like a U or an upside down U. If a in ax^2+bx+c is positive your min is the lowest y value and Max is infinity. The symbol for that is a sideways 8. But if a is negative than Max is the highest y value of the upside down U and min is negative infinity. Its kind of hard to explain this in paragraph form but hopefully this helps. :)

A quadratic has a maximum if it opens downward, and a minimum if it opens upward. This occurs at its vertex.