Higher November 2023 Paper 2 Q19
19.
Diagram not drawn to scale
Calculate the size of \(C\hat{B}D\). [7]
| Scheme | Marks | Comments |
|---|---|---|
| \((BC =)\ \sqrt{6.4^2 + 8.3^2 - 2 \times 6.4 \times 8.3 \times \cos(71)}\) | M2 | Allow alternative full methods throughout M1 for \((a^2) = 6.4^2 + 8.3^2 - 2 \times 6.4 \times 8.3 \times \cos(71)\) ( = 75.26…) |
| \((BC =)\ 8.67(5…)\) or \(8{\cdot}7\) (cm) | A1 | Allow A1 for an answer of 8.6 from correct working not from premature rounding |
| \(\sin(BDC) = \dfrac{\sin(68)}{11.1} \times 8.6(75…)\) | M2 | FT ‘their derived BC’ provided it is a length. M1 for \(\dfrac{\sin(BDC)}{8.6(75….)} = \dfrac{\sin(68)}{11.1}\) |
| (BDC = ) 46.4 to 46.6 (°) | A1 | Allow 47(°) from correct working. |
| (CBD = ) 65.4 to 65.6 (°) | A1 | Allow answers of 65(°) or 66(°) from correct working. FT provided both cosine and sine rule attempted and at least M1 awarded for each. |
| (7) |