**Exercise
Three: Solution (Algebraic)**

**Problem:**

Find the value of x for which A is a maximum. Also determine that maximum
value.

**Solution:**

Recognize that A is a quadratic function of x and that the graph of
the relationship

between x and A is a parabola. The maximum will therefore occur
at the vertex.

The x coordinate of the vertex is given by

Then

**Answer:**

A has a maximum value of 16 when x is 4.

Solution
(calculus)

Exercise
Two
Exercise
Four