ToolJuliaBeginner Eigenvalues with LinearAlgebra: normal modes of coupled oscillators @printf("eigen(Symmetric(A)): %7.4f %7.4f %7.4f\n", eigvals(Symmetric(A))...)w2 = eigvals(Symmetric(stiffness([0, k_bond, k_bond, 0])), Diagonal(masses_u .* u))