# Symbolic Integration problem with respect to a variable

8 views (last 30 days)
Waleed El-Badry on 3 Aug 2015
Commented: Walter Roberson on 3 Aug 2015
Hi, I wrote a simple script to calculate symbolic integration of multivariable with respect to "t" as below:
clear all
% Symbols in equation
syms c L Bita Gamma Eita t w a
% Function to be integrated
f=((Gamma*t/Eita)^(Bita-1))*(exp((Gamma*t/Eita)^Bita)*(a^(-t))-(t/w)*...
((Gamma*t/Eita)^(Bita-1))*(exp((Gamma*t/Eita)^Bita)*(a^(-t))));
f2=((Gamma*t/Eita)^(Bita-1))*(exp((Gamma*t/Eita)^Bita)*(a^(-t))*(1-(t/w)));
% Calculate the integral
R=(c*L*Bita)*(Gamma/Eita)*int(f,t,[0,w]);
R2=(c*L*Bita)*(Gamma/Eita)*int(f2,t,[0,w]);
The problem is result R and R2 are the same as the expression !

Sean de Wolski on 3 Aug 2015
Scroll down to the "Tips" section. Either int cannot find a solution or none exist.

#### 1 Comment

Walter Roberson on 3 Aug 2015
Even if you substitute in exact numeric values for all of the symbolic variables except t, you are unlikely to arrive at a formula that has a closed form solution. There might be some special cases with some of the constants being 0 perhaps.