| Exam Board | OCR MEI |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Year | 2007 |
| Session | June |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Completing the square and sketching |
| Type | Transformations of quadratic graphs |
| Difficulty | Easy -1.3 Part (i) is a straightforward substitution requiring solving x² - 4 = 21, which is basic quadratic equation solving. Part (ii) tests recall of the translation rule for functions (replacing x with x-2), requiring no problem-solving or insight. Both parts are routine C1-level exercises with minimal steps. |
| Spec | 1.02f Solve quadratic equations: including in a function of unknown1.02w Graph transformations: simple transformations of f(x) |
| Answer | Marks | Guidance |
|---|---|---|
| \(x^2 - 4 = 21\) | M1 | Setting \(y=21\) |
| \(x^2 = 25\), \(x = \pm 5\) | A1 | Both values |
| Answer | Marks | Guidance |
|---|---|---|
| \(y = (x-2)^2 - 4\) | B1 B1 | Correct translated equation |
## Question 9:
**(i)**
$x^2 - 4 = 21$ | M1 | Setting $y=21$
$x^2 = 25$, $x = \pm 5$ | A1 | Both values
**(ii)**
$y = (x-2)^2 - 4$ | B1 B1 | Correct translated equation
---9 (i) A curve has equation $y = x ^ { 2 } - 4$. Find the $x$-coordinates of the points on the curve where $y = 21$.\\
(ii) The curve $y = x ^ { 2 } - 4$ is translated by $\binom { 2 } { 0 }$.
Write down an equation for the translated curve. You need not simplify your answer.
\hfill \mbox{\textit{OCR MEI C1 2007 Q9 [4]}}