A few years ago, my boss suggested the HP48sx was not an accurate instrument based on his misunderstanding the following article:

The article defines two equations for calculating great circle distances and states the first equation listed is not very accurate depending on what calculation device or software is used. The author states the second equation is more accurate for all devices.

My boss assumed the HP48sx was not accurate due to the error margin in the result of the first equation. I would like to argue any TI calc would give similar results to the 48sx when using equation 1.

In a nutshell:

Equation 1 evaluated with Excel is accurate.

Equation 1 evaluated with HP48sx is not very accurate.

Equation 1 evaluated with TI-XX might not be very accurate either.

Equation 2 evalutated with Excel is accurate.

Equation 2 evaluated with HP48sx is accurate.

Equation 2 evaluated with TI-XX should be accurate.

Would equation 1 evaluated with a TI-XX be more accurate than an HP48SX? Unfortunately, the author of the article did not include several variables, such as a pair of lat/lons, or earth radius.

edit: fixed link.

*Edited: 9 Sept 2009, 7:11 p.m. *