Integration of a function which has limits in terms of parameters

11 visualizzazioni (ultimi 30 giorni)
Hi,
I have a function f3(t), defined as
clc; clear all;
syms t L rho m L n T k G v
N(t) = (T*L/2)*(n*pi/L)^2+k*sin(n*pi*v*t/L);
D(t) = (rho*L/2+m*(sin(n*pi*v*t/L))^2);
alpha(t) = N/D;
i = 6; j = 1
f3(t) = alpha(t)*cos(2*pi*i*t/L)*sin(2*pi*j*t/L);
I3 = int(f3,t,0,L)
when i am integrating the function f3(t) from limits 0 to L, the code is not giving me the output in the form of some expression. The output i am getting is in the form of int(f3,t,0,L), which I dont want. I want output in the form of expression (which will contain t L rho m L n T k G v).
Please help me with this!! Any help will be appreciated..
  5 Commenti
aakash dewangan
aakash dewangan il 15 Mag 2021
Modificato: aakash dewangan il 15 Mag 2021
Walter Roberson, thanks again for your reply and help.
Yes, you are right. I got integration output for a few combinations of parameter values (not for all values). Thanks for help.
"Do you have any suggestion for me to do this (integration) using any other approach / method / technique??"
Thanks,
Walter Roberson
Walter Roberson il 16 Mag 2021
I have no suggestions.
There just might be a change of variables available to make sin(n*pi*v*t/L) linear.
Is n*v known to be integer? If so then that would make a difference in the integration, as sin(n*pi*v*t/L) at t=L would be sin(n*pi*v) and if n*v were integer that would be 0 .

Accedi per commentare.

Risposta accettata

Jan
Jan il 14 Mag 2021
syms t L rho m L n T k G v
N(t) = (T*L/2)*(n*pi/L)^2+k*sin(n*pi*v*t/L);
D(t) = (rho*L/2+m*(sin(n*pi*v*t/L))^2);
alpha(t) = N/D;
i = 6; j = 1;
f3(t) = alpha(t)*cos(2*pi*i*t/L)*sin(2*pi*j*t/L);
I3 = int(f3, t, [0,L])
I3 = 
As Walter has said already: There is no closed form solution of this integral. You can simplify it only, if you provide specific values for the parameters.

Più risposte (0)

Community Treasure Hunt

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

Start Hunting!

Translated by