Programming Question on HP15CE

[tones688]

Hi,
So it's seriously been years since I used my 41CX and even then, I wasn't a programming guru. I recently picked up the 15CE and wanted to go thru the manual and learn the programming, etc..

The first example is to program a simple equation for time to fall from a certain height. The formula is: t = square root of 2H/g. When they make the program, it's straight forward and when they execute the program they just input the h and then execute the program and the correct answer is displayed. My question is, how did the program know that the value of H was inside the square root, for the life of me, I can't figure that out.. For those interested, the reference I'm reffering to can be found on pages 14 and 15 of the 15CE Collector Edition's user manual.

Thanks!