Optimization
Introduction
Optimization in calculus is determining the appropriate equation to describe a situation. You then take the derivative of that equation to find a turning point. This will usually be a minimum or maximum. The problems that require you to find the maximum height of a rocket are basic optimization problems.
For example,
Of all rectangles with perimeter 24cm, which dimensions yield the largest area?
A = LW Let x = length and (12 – x) = width.
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1.1 A field is already bounded on one side by a pre-existing fence. Three adjacent pens are to be enclosed by 800 feet of fence. Find the dimensions of the pens of maximum area (The pens are equal in area).
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1.2 ![]()
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b) Use the TI to find the minimum length (P + Q) and the location of E at this point.
Graph the function
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Look at the graph of the equation and use the minimum tool on the calculator to find a value of x. The TI will give you an answer of 2. The location is 2 units away from C.
c) Find the minimum (P + Q).
Substitute 2 in for x to find the length of (P + Q)
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d) Find the maximum (P + Q)
From looking at the graph we can tell that either point x = 0 or 6 are relative maximums of (P + Q). To find the value that yields the highest (P + Q) use the value function of a graph on the TI, or substitute in 0 and 6 and solve.
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