HP50g or other: U. of Houston calc exams

[Peter Murphy]

Back in November 2009, David Hayden linked to some calculator exams from the University of Houston's annual high school math contest. Now I find that many more of those exams are available, at

<http://mathcontest.uh.edu/>

I've learned a lot about using the 50g in solving problems in these exams, which at one time were explicitly intended for users of the TI-89/92. Perhaps others will profit from them as well.

In the 2015 exam, I solved problem 14 quickly on the 50g using the LAGRANGE function to do the fitting. I found problem 20 tedious, because the 50g provides no direct way (I think) to create a vector in polar coordinates from its radial and angular coordinates.

I'd be interested in seeing solutions to 2015 problem 23, and to any other problems whose solutions you think might help users of the 50g get better at using it.