[hailey51]

Can someone please explain how you find the max/min point for a formula? I need to be able to do it by hand.. not calculator..
so here's an example you can use:

f(x)=(x-3)(x-8)

[Unknown008]

There are several methods, but in the format you gave, the simplest way is by using your imagination and symmetry.

The expression (x-3) and (x-8) show that the quadratic has two roots, one at (3, 0) and the other at (8, 0). The middle point of the two is ([8+3]/2, 0), which is (13/2, 0), or (6.5, 0). 6.5 is the x coordinate of the turning point (min or max).

Since the coefficient of x^2 when you expand is positive, it's a minimum point. Then, just substitute the value of 6.5 in your equation to have the y coordinate.

y = (6.5-3)(6.5-8).