Find the characteristic polynomial of the matrix
$$ A = \left( \begin{matrix}1367&-1910\\-274&128\end{matrix} \right) $$The characteristic polynomial for matrix A is:
$$ p(\lambda) = \lambda^2-1495\lambda-348364 $$The characteristic polynomial is given by
$$ p(\lambda) = det(A - \lambda I) $$In this example we have:
$$ \begin{aligned} p(\lambda) &= det(A - \lambda I) = det \left( \left[ \begin{matrix}1367&-1910\\-274&128\end{matrix} \right] - \left[ \begin{matrix} \lambda & 0 \\ 0 & \lambda \end{matrix} \right] \right) = \\ &= \left| \begin{matrix}1367 - \lambda &-1910\\-274&128 - \lambda \end{matrix} \right| = (-\lambda+1367) (-\lambda+128) - (-1910) \cdot (-274) = \\ &= \lambda^2-1495\lambda+174976 - 523340 = \lambda^2-1495\lambda-348364 \end{aligned} $$