| Exam Board | AQA |
|---|
| Module | Further Paper 2 (Further Paper 2) |
|---|
| Session | Specimen |
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| Marks | 9 |
|---|
| Topic | Vector Product and Surfaces |
|---|
14 Given that the vectors \(\mathbf { a }\) and \(\mathbf { b }\) are perpendicular, prove that
\(| ( \mathbf { a } + 5 \mathbf { b } ) \times ( \mathbf { a } - 4 \mathbf { b } ) | = k | \mathbf { a } | | \mathbf { b } |\), where \(k\) is an integer to be found.
Explicitly state any properties of the vector product that you use within your proof.
[0pt]
[9 marks]
LL