| Exam Board | CAIE |
| Module | FP1 (Further Pure Mathematics 1) |
| Year | 2012 |
| Session | June |
| Topic | Invariant lines and eigenvalues and vectors |
5 The matrix \(\mathbf { A }\) has an eigenvalue \(\lambda\) with corresponding eigenvector \(\mathbf { e }\). Prove that the matrix \(( \mathbf { A } + k \mathbf { I } )\), where \(k\) is a real constant and \(\mathbf { I }\) is the identity matrix, has an eigenvalue ( \(\lambda + k\) ) with corresponding eigenvector \(\mathbf { e }\).
The matrix \(\mathbf { B }\) is given by
$$\mathbf { B } = \left( \begin{array} { r r r }
2 & 2 & - 3
2 & 2 & 3
- 3 & 3 & 3
\end{array} \right) .$$
Two of the eigenvalues of \(\mathbf { B }\) are - 3 and 4 . Find corresponding eigenvectors.
Given that \(\left( \begin{array} { r } 1
- 1
- 2 \end{array} \right)\) is an eigenvector of \(\mathbf { B }\), find the corresponding eigenvalue.
Hence find the eigenvalues of \(\mathbf { C }\), where
$$\mathbf { C } = \left( \begin{array} { r r r }
- 1 & 2 & - 3
2 & - 1 & 3
- 3 & 3 & 0
\end{array} \right) ,$$
and state corresponding eigenvectors.