Re: Simultaneous Equation Solver HP 33s Message #4 Posted by Ron Ross on 3 Mar 2005, 9:51 a.m., in response to message #3 by JJJ
A 3x3 is really trivial to implement. However, no matter how you do it, you are going to need 9 variables and more like 12 if you want to make it easier to use and manipulate. 15 if you don't want to destroy your existing variables or data (may need 15 anyway, if you don't make great use of the stack).
I suggest Cramers rule for finding determinets and staying with only using 9 variables (actually 10, you should store the determinet as well, rather than trust the stack). Although somewhat awkward, will only use 9 variables and will allow you to find value for whichever unknown you wish. If you need all three unknowns, you run the program 4 times, if you just need one, you run it twice.
Sadly, this is the limitation of 27 variables.
An Hp32s/32sii/33s just can't compare to a calculator such as the Hp42s. If you had one, it makes it even MORE difficult to use an Hp33s (I don't cry, I am not quite that emotional, but the Hp33s ain't no big leap. If people were evolving like calculators, we'd all be chimps about now! Hey wait a minute, I resemble that remark! 8o) )
Unfortunately, my batteries need changing on my 42s last week and YOU GUESSED IT! I lost several K of programs. Its to bad there was no serial port on the 42s. That, 32K and a units conversion feature like the 48G and I would never need another pocket calculater, nor would I ever look for one! But I guess marketing wins out, because then HP only makes ONE SALE!
Actually the Hp17Bii doesn't suffer from variable limitations, but it Ain't allowed on the NCEES exams either.
|