Consider the matrix B =

$\displaystyle

B = \begin{bmatrix} 1&-3\\1&1\end{bmatrix}

$

Find the eigenvalues 1 and 2 of B. Write eugenvalues in the form a+bi, where a; b E R.

When I solve for the determinant i get (1-/|(eigenvalue) )+3 and I'm stuck after because when i substitute a +bi instead of the eigenvalue I get a^2 + 2abi +b^2 +4 and it doesn't really help me.

If you know how to solve this I would really appreciate your help.Thanks!