June 2022 Paper 2 Q2
2 \(M\) is the midpoint of \(PQ\).
Not drawn accurately
Work out the value of \(a\). [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(-8\) | B2 | B1 correct equation or calculation eg \(\dfrac{a + 6}{2} = -1\) or \(a + \dfrac{6 - a}{2} = -1\) or \(-1 - 7\) or \(6 - 7 \times 2\) allow \(a\) to be any letter |
Additional guidance
| Answer \(-8\) (no need to check working) | B2 |
| Accept \((\ldots, -8)\) or \(\ldots, -8\) (no need to check working) | B2 |
| Allow working in vectors eg \(\begin{pmatrix} 2 \\ -1 \end{pmatrix} - \begin{pmatrix} 6 \\ 7 \end{pmatrix}\) | B1 |
| oe equations may involve equation of the line eg1 grad \(= \dfrac{6 - -1}{8 - 2} \qquad y = \dfrac{7}{6}x - \dfrac{10}{3}\) \(y = \dfrac{7}{6} \times -4 - \dfrac{10}{3}\) eg2 \(-1 - a = \dfrac{7}{6}(2 - -4)\) | B1 B1 |