how to solve an exponential equation with one unknown in matlab
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Alice Faisal
le 19 Juil 2018
Réponse apportée : Abraham Boayue
le 20 Juil 2018
I have an equation that need to be solved for rs, and I could'nt get the answer in matlab I have values for the other parameters and I need to get rs. But when computing it on MATLAB I dont get a correct answer This is the equation
exp((-pi*ra)/rs)+exp((-pi*rb)/rs)=1
ra=90.82*10^6 rb=90.23*10^6 so only rs in unknown
1 commentaire
Réponse acceptée
Abraham Boayue
le 20 Juil 2018
Try the following code which uses Newton's method to find the root of the f(x) = 0.
close all;
clc;
N = 50;
ra = 90.82e6;
rb = 90.23e6;
a = pi*ra;
b = pi*rb;
tol = 1e-10;
x0 = 0;
x = x0;
xn = x;
for k = 1:N
f = exp(-a*x) + exp(-b*x)-1;
fd = -(a*exp(-a*x) + b*exp(-b*x));
x = x-f/fd;
err = abs(x-xn);
xn = x ;
if err<tol
break;
end
end
rs = 1/xn;
disp(rs)
0 commentaires
Plus de réponses (1)
madhan ravi
le 20 Juil 2018
Modifié(e) : madhan ravi
le 20 Juil 2018
%Try this:
syms rs
ra=90.82*10.^6
rb=90.23*10.^6
rs=vpasolve(exp((-pi.*ra)./rs)+exp((-pi.*rb)./rs)-1,rs)
0 commentaires
Voir également
Catégories
En savoir plus sur Equation Solving dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!