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+--- Thread: [HP50G] DESOLVE Error: Bad Argument Type (/thread-16245.html)
[HP50G] DESOLVE Error: Bad Argument Type - dns.oliv - 01-29-2021 01:50 AM
I'm trying to solve a differential equation with DESOLVE, but I get bad argument type error message. Numeric, Approx and Complex CAS flags are disabled (actually I disabled all CAS flags).
Here is what I enter on RPN mode:
1. [ 'd1d1y(t)+5*y(t)=2*COS(t/2)' 'y(0)=6/5' 'd1y(0)=-1/2'] + ENTER
2. 'y(t)'
3. DESOLVE (LEFT SHIFT + 4[CALC] + F3[DIFF] + F1[DESOL])
Note: I'm using soft menus (flag 117 set).
Does anybody have any clue why I'm getting the error?
RE: [HP50G] DESOLVE Error: Bad Argument Type - peacecalc - 01-30-2021 12:38 PM
Hello dns.olic,
I keyed in:
1. 'd1d1y(t)=2*COS(t/2)-5*y(t)'
2. 'y(t)'
And use DESOLVE and I get a result with the two constants cC0 and cC1.
If I key in 'd1d1y(t)+5*y(t)=2*COS(t/2)' and not 'd1d1y(t)=2*COS(t/2)-5*y(t)', I although get an error message.
Same procedure with constrains, same behavior DESOLVE works with:
[ 'd1d1y(t)=2*COS(t/2)-5*y(t)' 'y(0)=6/5' 'd1y(0)=-1/2'] + ENTER
2. 'y(t)'
RE: [HP50G] DESOLVE Error: Bad Argument Type - Simone Cerica - 01-31-2021 10:06 AM
Hello,
it may be useful to read this tutorial:
Using Desolve
https://www.hpcalc.org/details/7291
https://www.hpcalc.org/hp49/docs/misc/usingdesolve.pdf
regards
Simone