One of the most important points on a function is the maximum or minimum.  For example, the most important point of a parabola (quadratic function) is the vertex, which is either the maximum or minimum, depending on which way the parabola opens.  

Example: Find the maximum for f(x) = -35x² + 120x + 440 

Step 1: Graph the function using the steps from Graphing a Function.
Step 2: Press 2nd (yellow button), CALC (above the blue menu button TRACE)
Step 3: Select 4: maximum.  Press ENTER.  You will be back at the graph screen.
Step 4: Press ENTER.  You will be back at the graph screen and will be prompted for a left bound.  Move the cursor to a point to the left of the vertex.  Then press ENTER.
Step 5: You will now be prompted for a right bound.  Move the cursor to a point to the right of the vertex.  Then press ENTER
Step 6: You will be prompted to guess where the vertex is.  Move the cursor to a point as close as possible to the vertex.  Then press ENTER.
Step 7: The answer will be displayed at the bottom of the screen.  In this example, the answer is (1.71, 542.86).

To find the minimum of the function, the process is very similar to above, with the exception of Step 3:

Step 3: Select 3: minimum.  Press ENTER.  You will be back at the graph screen. From here, continue with the directions above.

 

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This site was last updated 08/16/02 and is maintained by Donna L. Sperry