I use the command eig(A) to calculate the eigenvalues of the matrix A, in which k,α,β,γ are variables,
A=[-0.5*k -i*α 0;-i*α -0.5*γ -i*β;0 i*β -0.5k];
eig(A)
but the MATLAB shows "Undefined function or variable 'k'."
I don't know how to define the variables k,α,β,γ.
Can anyone tell me...