Question

Cameron said that the Y intercept of a quadratic function always tells the maximum value of the function. explain Cameron's error

Answer 1

Answer:

We can have two cases.

A quadratic function where the leading coefficient is larger than zero, in this case the arms of the graph will open up, and it will continue forever, so the maximum in this case is infinite.

A quadratic function where the leading coefficient is negative. In this case the arms of the graph will open down, then the maximum of the quadratic function coincides with the vertex of the function.

Where for a generic function:

y(x) = a*x^2 + b*x + c

The vertex is at:

x = -a/2b

and the maximum value is:

y(-a/2b)