[HP50G] DESOLVE Error: Bad Argument Type - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: General Forum (/forum-4.html) +--- 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