| Exam Board | CAIE |
| Module | FP1 (Further Pure Mathematics 1) |
| Year | 2015 |
| Session | June |
| Topic | Invariant lines and eigenvalues and vectors |
10 The matrix \(\mathbf { A }\) is given by
$$\mathbf { A } = \left( \begin{array} { r r r }
2 & 2 & - 3
2 & 2 & 3
- 3 & 3 & 3
\end{array} \right)$$
The matrix \(\mathbf { A }\) has an eigenvector \(\left( \begin{array} { r } 1
- 1
1 \end{array} \right)\). Find the corresponding eigenvalue.
The matrix \(\mathbf { A }\) also has eigenvalues 4 and 6. Find corresponding eigenvectors.
Hence find a matrix \(\mathbf { P }\) such that \(\mathbf { A } = \mathbf { P D P } \mathbf { P } ^ { - 1 }\), where \(\mathbf { D }\) is a diagonal matrix which is to be determined.
The matrix \(\mathbf { B }\) is such that \(\mathbf { B } = \mathbf { Q A Q } ^ { - 1 }\), where
$$\mathbf { Q } = \left( \begin{array} { r r r }
4 & 11 & 5
1 & 4 & 2
1 & 2 & 1
\end{array} \right)$$
By using the expression \(\mathbf { P D P } ^ { - 1 }\) for \(\mathbf { A }\), find the set of eigenvalues and a corresponding set of eigenvectors for \(\mathbf { B }\).
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[Question 11 is printed on the next page.]