Thank you Heidi—I'm glad you enjoyed it!

Hi Heidi—thanks for catching these issues! Because the final exam is generated on a per-person basis, I can't know which questions you're talking about. Would you mind sending these comments along with screenshots of the questions to wolfram-u@wolfram.com? Thank you!

Hi, having participated in the daily sessions, I am able to work on the quizzes and start the final. I have only watched a couple of videos, it seems to be of no consequence.

There is a typo in the Final Exam section of the online course. It says

Demonstrate your proficiency by becoming Wolfram Certified Level I in differential equations

Quiz 4 - Question 2: I don't see a correct answer, don't agree with answer quiz is looking for.
Quiz 4 - Question 7: I do see a correct answer, don't agree with answer quiz is looking for. I may be missing something.

Hi Arben;

Thanks so much, that is exactly what I wanted on the stacked plots. By the way, you performed some really slick programming, I learned a lot.

Thanks Again, Mitch Sandlin

Lesson 21, Slide 7 says: As you can see, the degree and the classification do not have anything to do with each other.

I don't believe that statement is true - degree must be >= number of terms -1.

degree of monomial >= 0; degree of binomial >= 1; degree of trinomial >= 2

degree of polynomial (with four or more terms) >= 3.

Thanks so much, what you sent is really close to exactly what I wanted. After making a very few modifications to what you sent, I attempted to place points where the wave crossed the x-axes on the last plot and ran into a small problem - see attached notebook.

My plan was to make small points on the top plot where the points cross the x-axes (Rest Positions), medium sized points on the middle plot (Critical Points) and large points on the last plot (Inflection Points) with a legend at the bottom indicating what each sized plot represents. Part of the problem is that the x-axes is no longer at zero using GraphicsColumn[] and I am not sure how to determine the location of the points.

Incidentally, the way you used Range[] to distribute the Ticks across the plot was really neat.

Thanks,

Mitch Sandlin

Attachments:

PlotWork1.nb

Hi;

In my attached notebook, I have 3 sinusoidal plots grouped together using GraphicsColumn[]. On the 3rd plot, I used Pi for my ticks. What I would like to do is eliminate the other ticks on plot 1 & 2 and instead use vertical dashed lines through all the plots where the sinusoidal crosses the x-axes of all 3 plots. Even after reading all the documentation, I still cannot figure out how to create the vertical dashed lines through all 3 plots.

Thanks,

Mitch Sandlin

Attachments:

PlotWork.nb

Thank you for the kind words and correction, John! I'll get that fixed.

Hi Mitch—this is certainly beyond the scope of this course, but I'll respond here given that I know the answer. Two things come to mind: the first is a bit trivial, but it works—simply multiply your result by {1,180 Degree/Pi. So for your code,

{1,180 Degree/Pi}*ToPolarCoordinates[FromPolarCoordinates[{5, 36.87 °}] + FromPolarCoordinates[{10, -53.13 °}]]

Alternatively, you could construct it like:

MapAt[180 Degree/Pi*#&,yourData,2]

This is nice in that it's extensible to a list of {r,theta} pairs just by doing:

MapAt[180 Degree/Pi*#&,yourData,{All,2}]

Hopefully that helps.

Hi Paul—the exercises will be available once the course has been fully deployed via our Wolfram U MOOC framework. We're working on that, but in the meantime the extra exercises will not be available.

Hi Arben;

Since I am working in degrees, I would like the output is degrees as well. However, Mathematica insists on giving my output in radians. In my example, I am adding two polar coordinates, with the first number in each coordinate is the magnitude and the second is the angle (in degrees). How is the best way to get my output in degrees?

Thanks,

Mitch Sandlin

ToPolarCoordinates[FromPolarCoordinates[{5, 36.87 °}] + FromPolarCoordinates[{10, -53.13 °}]]