1. GOAL SEEK AND SOLVER Both of these tools come with the standard Excel package, but Solver has to be installed. If it is not on your computer, do the following: Open Excel and go to Tools|AddIns After clicking AddIns, you’ll get a drop- down menu; scroll down to Solver Add-in and click the box.

2. GOAL SEEK AND SOLVER Suppose we’re trying to graph the Equation y = x^3-2x^2-3x-121 We can do this in Excel as follows:

3. GOAL SEEK AND SOLVER

4. Now we want to find the x such that the corresponding y is 21. You can tell from the table that the value will be somewhere between 5 and 6. To solve for it, we go to the Excel command Tools|Goal Seek.

5. GOAL SEEK AND SOLVER

6. We can do the same calculation with Solver.

7. GOAL SEEK AND SOLVER

8. The difference between Solver and Goal Seek. Solver remembers, Goal Seek forgets Solver is more flexible We use the function y = x^2-7x-14

9. GOAL SEEK AND SOLVER

10. There are two roots. If you use Goal Seek, you cannot specify which x to find. With Solver, however, you can specify constraints on the variables:

11. GOAL SEEK AND SOLVER