Math problem where graphing calculator may slow you down...

11152014, 12:45 PM
(This post was last modified: 11152014 09:36 PM by Gilles.)
Post: #14




RE: Math problem where graphing calculator may slow you down...
With HP50G,approx mode (but exact mode is OK):
Code: 'SIN(X)=COS(X)' SOLVEVX Code: { 'X=EXP(6.2832*n2.3562)' Note that Lsub is a program I use for  (or SUBST) when equations are in a list (list processing don't work with  or subst) : Code: « 1 >LIST {  } + >PRG MAP » I also often use Lexr to get only the right part of equations in a list : Code: « 1 « EXLR NIP » DOSUBS » { 'X=EXP(6.2832*n2.3562)' 'X=EXP(6.2832*n+0.7854)' } Lexr gives { 'EXP(6.2832*n2.3562)' 'EXP(6.2832*n+0.7854)' } and for example to test n from 5 to 5, continue with STEQ {} 5 5 FOR a EQ 'n' a 2 >LIST Lsub + NEXT XNUM SORT that gives { 2.1526E15 4.9812E14 1.1527E12 2.6674E11 6.1725E10 1.4284E8 3.3053E7 7.6487E6 0.0002 0.0041 0.0948 2.1933 50.7540 1174.4832 27178.3539 628925.9347 14553781.7413 336784589.923 7793428678.94 180345337617. 4.1733E12 9.6573E13 } In exact mode you get { 'EXP(2*ATAN(1+√2)2*PI)' '1/EXP(2*ATAN(1+√2))' 'EXP(2*ATAN(1+√2))' } As you see the HP don't simplify the ATAN (but you can write easily your own program for trivial trig simplifications with a serie of MATCH commands. But it's not automatic and rather slow). I can post this if there is some intesrest with the Prime solve(sin(ln(x))=cos(ln(x))) returns directly the symbolic simplified general solution... ( 'principal' uncheck in CAS setting) It would fine if we could do : equation  n={1,0,1,2} or equation  n={5...5} to obtain a list of equations for each value. But this dont work .... So I do this: Edit the general solution to change n_xxx by n then f(n):=ANS concat(f(1),f(0)) concat(ANS,f(1)) concat(ANS,f(2)) sort(ans) ~= and you get the result (approx or exact) 

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