Lines and slopes and intercepts, oh MY!

Howdy, related to my posts about using Excel in Calculus, I have this project that I use on lines and slopes and intercepts.  Again, it is a gentle introduction to programming cells in Excel.  In this one, I have students vary each of the three parameters individually and examine what effect the changes have on the values of the slope and the intercepts. 

Again, the point of these is to start having students learn to use a spreadsheet, and to also examine the idea of playing with parameters. 

Again, DM me on twitter or elsewhere if you want the files.

 *** Instructions start here ***

  All of the lines we look at in this project will be of the form Ax + By = C 

1.       Replace the fake ID number with your own Blinn ID number.  (Purple boxes)

2.       In the yellow background boxes, we will keep B and C the same, and change the value of A.  Notice that the template will automatically give you the different values of A.  You will need to program Excel to compute the slope and the coordinates of the two intercepts.

a.       As you increased the values of A, did the slope increase or decrease?  Explain why this would have to be so.

b.       Which coordinates changed, and in which direction?

c.       Which coordinates stayed the same?

d.       Describe visually what in effect we were doing with the line.  (so, spinning it about a specific point, sliding it up or down, both, neither, etc)

3.       In the green boxes, we will keep A and C the same, and change B.  ** Same four questions

4.       In the blue boxes, we will keep A and B the same, and change C.   ** Same four questions

5.       So which change seems to have the biggest effect on the slope, and why does that work?

 The numbers from the first half.

The numbers from the other two sets of variations.

Excel Projects in Calculus part 5

If you need background, see my first post:

First Excel in Calculus post.
** If you want the Word and Excel copies, @me (@robebymathdude) on Twitter **

The last of my Excel projects in Calculus posts.  I did five mainly because I also have the students do memos (see  ) and there are only so many weeks in the semester.  I made it a point when laying out the schedule to not have a memo or project due during an exam week, so that is one reason for having five.  The other is the grading load!

Anyway, in this project I wanted the students to explore Riemann Sums but in a way that involved more than just calculating the sums.  (If you didn’t know, sites like Wolframalpha will do a Riemann sum with ease.  See for example: Example Sum

I also wanted the students to try and go back to a function, so I had them do sums for 1/x, and then see that the basic log rules worked.  I had a few students who figured this out, but the majority just kinda shrugged on their answers.  I am going to have to think about how to get students to this point in a better / different way for next time.

Thanks for reading.