Effacer les filtres
Effacer les filtres

How can i solve this equation ?

3 vues (au cours des 30 derniers jours)
Mallouli Marwa
Mallouli Marwa le 18 Jan 2017
Hi
How ca i solve the attached equation to find lamda ?
When all the other terms are known.

Réponse acceptée

Jorge Mario Guerra González
If you want to get multiple answers use vpasolve function. Set the number of answers you want yo get and the code will pick some then in a random way.
syms lambda
Mt=1; % The value of your variables
m=1;
L=1;
lt=1;
eqn= 1+(cos(lambda)*cosh(lambda))+((lambda*Mt/(m*L))*(cos(lambda)*sinh(lambda)-sin(lambda)*cosh(lambda)))-((lt*lambda^3)/m*L^3)*(cosh(lambda)*sin(lambda)+sinh(lambda)*cos(lambda))+ ((Mt*lt*lambda^4)/m^2*L^4)*(1-cosh(lambda)*cos(lambda)) ==0;
for n = 1:50
vpasolve(eqn,lambda,'random',true)
end
this example gives you 50 answers. The answer before gives the first it finds.
  3 commentaires
Mallouli Marwa
Mallouli Marwa le 20 Jan 2017
How can i display this result in a vector
for n = 1:50 vpasolve (eqn,lambda,'random',true) end
Jorge Mario Guerra González
syms lambda
Mt=1; % The value of your variables
m=1;
L=1;
lt=1;
eqn= 1+(cos(lambda)*cosh(lambda))+((lambda*Mt/(m*L))*(cos(lambda)*sinh(lambda)-sin(lambda)*cosh(lambda)))-((lt*lambda^3)/m*L^3)*(cosh(lambda)*sin(lambda)+sinh(lambda)*cos(lambda))+ ((Mt*lt*lambda^4)/m^2*L^4)*(1-cosh(lambda)*cos(lambda)) ==0;
k=zeros(1,50);
for n = 1:50
k(i)=vpasolve(eqn,lambda,'random',true)
end
that should create the vector

Connectez-vous pour commenter.

Plus de réponses (1)

Jorge Mario Guerra González
Just use the function solve, which uses numerical techniques to find variables.
try this.
syms lambda
Mt=1; % The value of your variables
m=1;
L=1;
lt=1;
%check if I wrote this correctly
eqn= 1+(cos(lambda)*cosh(lambda))+((lambda*Mt/(m*L))*(cos(lambda)*sinh(lambda)-sin(lambda)*cosh(lambda)))-((lt*lambda^3)/m*L^3)*(cosh(lambda)*sin(lambda)+sinh(lambda)*cos(lambda))+ ((Mt*lt*lambda^4)/m^2*L^4)*(1-cosh(lambda)*cos(lambda)) ==0;
value=solve(eqn,lambda) %solution for lamda
  2 commentaires
Mallouli Marwa
Mallouli Marwa le 19 Jan 2017
This equation must have an infinite solutions but this method show only one solution.
John D'Errico
John D'Errico le 19 Jan 2017
You cannot find an infinite number of solutions. If you tried to write them all down, it would take infinitely long.

Connectez-vous pour commenter.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by