# Week 4

## Topics

There is no new mathematics material this week. You will be required to use Excel to do some of the things you have been doing by hand so far, such as evaluating functions, graphing them, or solving equations. You are allowed to use Excel (with an initially empty worksheet) as a calculator during exams.

## Excel Tutorial 1 (Spreadsheet, Video): Graphing and Goal Seek

We suggest you read the spreadsheet or watch the video linked above. You can also look at the Excel Help page. You should at least read the sections about Versions of Excel and the Excel tutorials.

There are two things in Excel you should learn this week:

• Simple Graphing
At this point we do xy charts only (graphs of functions in an xy-coordinate system). We will do some more graphing (bar charts, pie charts) in chapter 8. Excel Tutorial 1 explains about graphing.
Here is a quick summary: To make a graph, you need to prepare a column of x-values and one or more columns of y-values, and select them both with the mouse. If you include headings with your data columns, they will be put on the graph as labels.

• Excel 2007/2010: Select Insert --> Scatter.
• Excel 2011: Click 'Charts --> Scatter'

• Solving Equations with Goal Seek
The Goal Seek tool can solve any equation of the form f(x) = constant. Excel Tutorial 1 explains how to use it.
Goal Seek is usually installed by default in Excel. In Excel 2007/2010/2011 it is under Data --> What If Analysis. If your machine doesn't have it, look at the instructions for installing the Solver on the Excel Help page. Installing Goal Seek works the same way. You should also look at the Excel Help page for instructions on how to increase the accuracy of Goal Seek.
Here is a quick summary of Goal Seek: To solve f(x)=0, you choose one cell for x and one for f(x). Put some number into the x cell, and enter the formula into the f(x) cell.
For example, suppose you want to solve x-cos(x)=0. You decide to use A2 for x and B2 for f(x), and put some labels in A1 and B1, so you can remember yourself what you are doing. Put some random number (like 0) into the x cell, and the formula "=A2-cos(A2)" into the f(x) cell.
Call up Goal Seek, and fill out the blanks:
Set cell: [click on the f(x) cell]
To value:
0
By changing cell:
[click on the x cell].
Here is a screen shot:

x is in A2, f(x) is in B2. (The x in A1 and f(x) in B1 are labels; the values are in A2, B2).
This will find a solution near the value of x that you put in. To find multiple solutions, repeat the goal seek with different values of x. The accuracy of the Goal Seek function is not very high; f(x) usually ends up as 10-5 instead of 0.

## Excel Homework 1

The Excel Homeworks are quite short, just 2 or 3 problems, but problems that are so complex that you have to use some sort of technology to solve them.

We will teach you how to do these problems in Excel, but we can't control that you actually do them in Excel. Some of them can be done with a graphing calculator, or other tools. The choice is up to you.

Maybe we should really call them Technology Homeworks, but since we teach Excel (and nothing else), we'll stick with Excel Homeworks.

Special note about Excel Homework 1: You have to increase the default accuracy of the Excel Goal Seek in order to do this homework. Look at the Excel Help page for instructions.

## Exam Policies Homework

The exam policies are listed in the Exam Policies document. It is your responsibility to read this document, and to be aware of the rules. You are required to complete an Exam Policies Homework with a 100% score before you are allowed to take the practice exam and then the exam. It is not counted toward to the grade. It is just for you to be aware of the exams rules since they are so important.

## Practice exam 1

For the homeworks so far, you had all sorts of help available: links to the text book, worked out examples, step-by-step solutions, sometimes even videos, immediate feedback after each question, unlimited repetitions.

Things will be different on the exam: no outside help; no feedback until you have finished the whole thing; no second tries, except for the exam as a whole; a 60 minute time limit; a limit of 3 tries altogether.

By popular demand, we have put in practice exams, so you can get used to the feeling. The practice exam is similar to the reaexam, just a little shorter, and it has very little credit. Yes, you can cheat on the practice exam, and nobody will find out, but you are just cheating yourself. The improvement in the actual exam will more than make up for a slightly lower score on the practice exam.

You cannot take the actual exam until you have attempted the practice exam at least once, with a score of at least 10%. If you cannot do that, you are definitely not ready for the exam. The practice exams are counted toward your final grade. The password for all practice exams is 'practice'.

## exam 1

exam 1 covers the material from the first three weeks: Appendix A, Chapters 1 and 2.

You are allowed to use Excel (with an initially empty worksheet) as a calculator during the exam.

The MyMathLab grader is very picky about the form of the answers. Expect to lose some points because you didn't understand what it wanted exactly. You should have run into that on the homework already. Between the practice exam and the actual exam, you have an additional 6 tries to get it right.

## Assignments

• Go through the Excel Tutorial 1 spreadsheet or watch the video.
• Complete Excel HW 1
• Review the Exam Policies, and take the Exam Policies homework. You have to pass with a 100% score before you can take the practice exam or the exam. This homework will not count towards your overall score, we just want to make sure that you have actually read the policies.
• Take Practice exam 1 (at home, or anywhere else; the password for all practice exams is practice).
• Take exam 1. The exam has a time limit of one hour

Last Updated: Wednesday, August 5, 2015