IB skill practice

Use vector products in geometric proofs

Use dot and cross products to justify geometric relationships.

Paper 1, Paper 2 5 marks Difficulty 5

Use vector products in geometric proofs - verification step

In a vector proof, \(|\mathbf{a}|=20\), \(|\mathbf{b}|=8\), and \(\sin\theta=3/4\). Enter \(|\mathbf{a}\times\mathbf{b}|\), the area of the parallelogram formed by the two vectors.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.