evet sembolik çalişiyorum. yeni yeni isindiriyorum kendimi matlaba. script de şu şekilde:
clear all
clc
syms x
k=(2+3*x)*cos(pi*x/3);
f=sin(pi*x/3);
%shape functions
fi = [x;x^3;x^5];
%stiffness matrices
for i=1:3
for j=1:3
K(i,j)=0;
K(i,j)=int(k*diff(fi(i,1),x)*diff(fi(j,1),x),x,0,1);
end
end
%force vectors
for i=1:3
F(i,1)=int(f*fi(i,1),x,0,1);
end
%%Ritz Coefficients and Displacements
%for N=1
a1=K(1,1)^-1*F(1,1);
a1 = double(a1)
u1=a1*fi(1,1)
%for N=2
a2=K(1:2,1:2)^-1*F(1:2,1);
a2=double(a2)
u2=a2(1,1)*fi(1,1)+a2(2,1)*fi(2,1)
%for N=3
a3=K(1:3,1:3)^-1*F(1:3,1);
a3=double(a3)
u3=a3(1,1)*fi(1,1)+a3(2,1)*fi(2,1)+a3(3,1)*fi(3,1)
0