# plotting – Mathematica returns an empty plot for the real part of the eigenvalues

I have a 3*3 matrix. Using Mathematica I have found the eigenvalues in terms of “K”. The problem arises when I’m plotting the real part of eigenvalues against “k” (k is a positive number ranging from 0.02 to 0.05). Can someone guide me, why I’m getting empty?

``````(*Here is my Matrix*)

J1 = {{-v^2 - w^2 - F - D1*k^2, -2*u*v, -2*u*w}, {v^2,
2*u*v - (F + k1) - D2*k^2, 0}, {w^2, 0,
2*u*w - (F + k2) - D3*k^2}};

(*I have defined the eigen values as the function of the following
parameters*)
{λ4(F_, D1_, D2_, D3_, k1_, k2_, u_, v_,
w_), λ5(F_, D1_, D2_, D3_, k1_, k2_, u_, v_,
w_), λ6(F_, D1_, D2_, D3_, k1_, k2_, u_, v_, w_)} =
Eigenvalues(J1);

(*Here are the numerical values of the parameters*)
{λ4(0.025,
290, 61.443, 11, 0.0043, 0.046, 0.381, 0.0767, 0.186), λ5(
0.025, 290, 61.443, 11, 0.0043, 0.046, 0.381, 0.0767,
0.186), λ6(0.025, 290, 61.443, 11, 0.0043, 0.046, 0.381,
0.0767, 0.186)};

(*Plotting the real part of the eigen values against k*)
Plot({Re(λ1), Re(λ2), Re(λ3)}, {k, 0.01, 0.05},
PlotStyle -> {{Thick, Red}, {Thick, Blue}}, Frame -> True,
FrameLabel -> {Style("k", 18), Style("Re(λ)", 18)})
``````