Part of Standard Excel Installation Finds the root of a scalar function. GOALSEEK. Recall that root-finding methods (e.g., bisection method, Newton’s method) rely on a change in sign of the objective function Any f(x) function used in GOALSEEK should have a well defined sign change.
Use Excel’s GOALSEEK feature to find the root of f(x) = x – cos(x) between 0 and 1.GOALSEEK - Example
Highlight cells that will be named. Under Formulas Tab select Create from Selection
Goal Seek found on Data Tab under “What-If Analysis”
Uses a gradient-based method (like Newton’s method) to find the root or the max/min
Works very well for functions that have a well-defined minimum (or maximum), like a quadratic form (a parabola)SOLVER
Go to Excel Options
Go to Add-Ins Tab on left and click Go at bottom
Make sure Solver Add-In is checked and click ok
Now go to Data tab and click on Solver on the far right
Use named range to create a target cell ‘fxy’SOLVER - Example
Type the formula into the target cell (“=(xval-5)^2 + (yval-5)^2”)SOLVER - Example
Solver is found on far right of Data tab
To have the value of the target cell be as large as possible, click Max.
To have Solver automatically propose the adjustable cells based on the target cell, click Guess.