akcs.brentlz@hpcvbbs.UUCP (Brent Ellzey) (01/28/91)
As to your first question...I don' believe that the 48 can solve
diff-eq's directly entered as alebraic objects. As I understand it,
the 48 uses patern matching of built in (and user defined) functions
to symbolically integrate/differentiate...A numerical method would
more than likely be necessary to solve diff-eq's...
2) Yes, there are ways to manipulate algebraics...I don't know
about being "easier"...see chapter 22: Algebra in volume 1
of the Owner's manual.
3) "An Easy course in Using the HP-48SX" is available from
Grapevine Publications for $22.00
P.O. Box 2449, Corvallis, OR 97339-9960 1-800-338-4331
the info I have says to add $10.00 for postage to Canada...
This may also be available from Educalc, 27953 Cabot Road,
Laguna Niguel, CA 92677 USA...They also charge $10.00 fo
r shipping to Canada...
Although I haven't seen this book, I can feel relatively safe
in suggesting it as Grapevine is known for high quality
publications( Really, I don't work for them :-)
Hope this was helpful...Brent Ellzey
Aerospace Engineering( undergrad )
University of Arizona...go Wildcats!billw@hpcvra.cv.hp.com. (William C Wickes) (01/29/91)
The Mathematical Applications book for the HP 28 contained programs for solving 2nd-order linear DEQ's, including the inhomogeneous case where the inhomogeneous part could contain any sum of exponential terms. Those programs should run unchanged on the HP 48. Educalc has this book at $9.95 (it's a "Step-by-Step" book). Bill Wickes HP Corvallis
c_s244010117@stat.appstate.edu (01/29/91)
> the 48 uses patern matching of built in (and user defined) functions > to symbolically integrate/differentiate...A numerical method would > more than likely be necessary to solve diff-eq's... This may be true, but there are ways of making it easier to solve higher order d.e.'s! Using Wayne Scott's polynomial routines to find the roots of the characteristic polynomial makes finding the homogeneous solution of a higher order d.e. a breeze! If you have a non-homogeneous equation that can be solved using undetermined coefficients, all you have to do is enter your d.e. and your solution with undetermined coefficients [store this one in Y if using dX(dX(Y))]. Make sure your d.e. is at stack level 1, and evalutate it until it doesn't change. Equate coefficients and solve the resutling equations! Its easier than it sounds, and it is really helpful. As far as first order d.e.'s, I don't know how to accomplish these.........