how to solve log log equation??

2 vues (au cours des 30 derniers jours)
mahmoud abougharara
mahmoud abougharara le 23 Déc 2023
Modifié(e) : Torsten le 23 Déc 2023
clc ,clear
syms m
m1=7;
m2=9.41;
t1=273+30;
t2=273+50;
t=40+273
t = 313
b=(log10(log10(m1))-log10(log10(m2)))/((log10(t1)-(log10(t2))));
a=log10(log10(m1))-b*log10(t1);
a
a = -5.5678
b
b = 2.2143
log10(log10(m))=a-b*log10(t);
Error using indexing
Invalid indexing or function definition. Indexing must follow MATLAB indexing. Function arguments must be symbolic variables, and function body must be sym expression.
solve(m)
  1 commentaire
Matt J
Matt J le 23 Déc 2023
Why not as written?

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Réponses (1)

Sulaymon Eshkabilov
Sulaymon Eshkabilov le 23 Déc 2023
Here is the corrected code (note how the EQN is set up for the given equation):
clc, clearvars
syms m
m1=7;
m2=9.41;
t1=273+30;
t2=273+50;
t=40+273;
b=(log10(log10(m1))-log10(log10(m2)))/((log10(t1)-(log10(t2))));
a=log10(log10(m1))-b*log10(t1);
fprintf('a = %f; b = %f \n', [a, b])
a = -5.567761; b = 2.214304
EQN =log10(log10(m))==a-b*log10(t);
SOL = solve(EQN);
fprintf('Solution: m = %1.16f with solve() \n', double(SOL));
Solution: m = 1.0000000000185594 with solve()
  1 commentaire
Torsten
Torsten le 23 Déc 2023
Modifié(e) : Torsten le 23 Déc 2023
Or
m = 10^(10^(a-b*log10(t)))

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