Question

How to find the maximum or minimum value of a quadratic function?

Answer 1

You look at the vertex. Are you at the calculus level or the algebra level?

Answer 2

see the sign of x^2 coeffecient

Answer 3

Algrebra II, year three in high school. It's the same as the vertex?

Answer 4

correct, vertex gives us max/min value.

if x^2 coefficient is -ve, its min
if x^2 coefficient is +ve, its max

Answer 5

its the opposite actually.

if x^2 coefficient is -ve, its max
if x^2 coefficient is +ve, its min

Answer 6

What @ganeshie8 said, that will tell you whether the parabola faces up or down. The point at the vertex will be a min or a max depending on that coefficient.