Pass symbolic variables or simply symbolic variable?

syms epsilon_x epsilon_y gamma_xy N_x
[N_x; 0;0 ]=[11628 1494 0; 1494 11628 0; 0 0 1839]*[epsilon_x; epsilon_y; gamma_xy]
epsilon_y=solve(0 == [1494 11628 0]*[epsilon_x; epsilon_y; gamma_xy], epsilon_y)

I have declared symbolic variables but how do I solve for N_x in terms of only epsilon_x? I've have solved for epsilon_y in terms of epsilon_x but it doesn't replace epsilon_y when I try to solve for N_x

Answer 1

[Birdman]

Try the following. sol2 will give you the solution of N_x in terms of epsilon_x.

syms epsilon_x epsilon_y gamma_xy N_x
eq=[N_x; 0;0 ]==[11628 1494 0; 1494 11628 0; 0 0 1839]*[epsilon_x; epsilon_y; gamma_xy]
sol1=solve(eq(2),epsilon_y);
eq(1)=subs(eq(1),epsilon_y,sol1);
sol2=solve(eq(1),N_x)