# FAQ For Lab 1

• Entering functions
• We are having trouble entering the function into Excel.

Three things are worth noting here:
• Excel does not recognize the symbol pi, so you cannot enter pi by typing the character. However, Excel does have a function PI() that returns the value of pi. (It takes no arguments, so =PI() returns about 3.14159265, while =2*PI() returns about 6.28318531, and =SIN(2*PI()) returns about 0.)
• Excel does have a built in function SIN().
• Remember that Excel requires some sort of operator between any two values. (You can't use a space to mean multiplication.) So while =SIN(12 B2) will not produce a value, =SIN(12*B2) will.
• Setting up Simpson's Rule

• How do we figure out delta x in Problem 5?

You figure out delta x in the same way we usually figure out delta x: you should use the formula (b - a)/n to calculate delta x. (Here, a and b are the beginning and end of your interval, and n is the number of subintervals you wish to use.)

Once you know delta x, you can use Edit->Fill->Series to fill in a set of x values, like you did when you graphed. (See the Graphing Instructions for more details.)

• Our Simpson's rule calculation in Problem 5 only gives error messages; what's wrong?

Many things could be wrong. Double check the following:
• Make sure you have not left out multiplication symbols (*) or division symbols (/) between terms in your formuals. (Excel does not let you multiply by saying "2 E4" for example; you must say "2*E4".)
• Make sure you have calculated delta x and entered this value into the calculation. There is no cell which does your calculation for you in Problem 5 like we had in the Simpson's rule worksheet. You will have to figure out what delta x is and type in the number in the formula.

• Write-Up
• Do we need to print out the Simpson's rule worksheet for each problem?
No; the Simpson's rule worksheet is for you to complete the calculations you need during the lab. It will also be useful for you at other times, as it will allow you to approximate integrals quickly. But you do not include the worksheet as part of your write-up. All you need to include is the peach results table from each calculation, showing the result of using Simpson's rule with 2, 4, 18, 16, and 32 subintervals

• Our graph is on a sheet in the workbook; how do we put it into a document?

You have selected "As a new sheet" rather than "As an object" in the last stage of the Chart Wizard. You can fix this by right clicking on the sheet with the graph (control-click on a Mac), and selecting "Location" from the pop-up menu. Choose "As an object in" (some worksheet). Then you can select, copy and paste, move, and resize the graph any way you want.

• Our graphs are too big to fit on the page with the other information; how can I make them smaller?

If you click on the box containing the graph to select it, you can then resize the graph by grabbing one of the resize handles with the mouse and dragging the handle. The resize handles will look like the tiny black boxes in the picture below:

Note: You will see more of your graph if you make sure to eliminate the legend when you plot, as the legend is not needed in this graph.