Foundation June 2017 Paper 2 Q22
22
Not drawn accurately
Work out the value of \(x\) as a decimal. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(8^2\) and \(3^2\) seen or \(8 \times 8\) and \(3 \times 3\) seen or 64 and 9 seen or 55 | M1 | M2 for \(\sin^{-1}\left(\dfrac{3}{8}\right) = 22.(\ldots)\) and \(8\cos(\text{their } 22.(\ldots))\) or \(\cos^{-1}\left(\dfrac{3}{8}\right) = 67.(\ldots)\) or 68 and \(8\sin(\text{their } 67.(\ldots))\) |
| \(\sqrt{8^2 - 3^2}\) or \(\sqrt{64 - 9}\) or \(\sqrt{55}\) | M1dep | |
| [7.4, 7.42] | A1 |
Additional guidance
| \(\sqrt{8^2 + 3^2}\) or \(\sqrt{64 + 9}\) or \(8^2 + 3^2\) or \(64 + 9\) | M1M0depA0 |
| Only \(\sqrt{73}\) or only 73 or only 8.5... | M0 |
| If trigonometry used it must be a fully correct method that would lead to the correct value of \(x\) | |
| Partial method using trigonometry | M0 |
| Ignore units given | |
| 8 cm\(^2\) is not \(8^2\) unless recovered | |
| Correct answer in range seen, ignore further work if truncates or rounds | M2A1 |
| \(8^2 = 16\) and \(3^2 = 6,\ \sqrt{16 - 6}\) | M1M1depA0 |
| Scale drawing with answer in range [7.4, 7.42] | M2A1 |
| Scale drawing with answer not in range [7.4, 7.42] | M0 |