Question

what is an example of a quadratic function that has maximum value? and how do you know that it has a maximum?

Answer 1

y = -x^2 is a quadratic function with a maximum because it is concave down -- the function looks like an upside down U, and as such it has a maximum. y=x^2 has no maximum, but because it looks like a U, it has a minimum.

Answer 2

thanks