Edexcel C2 — Question 7 11 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Marks11
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicAreas Between Curves
TypeCurve-Line Intersection Area
DifficultyModerate -0.3 This is a standard C2 integration question requiring finding intersection points by solving a quadratic equation, then computing a definite integral of the difference between two functions. While it involves multiple steps, the techniques are routine and well-practiced at this level, making it slightly easier than average.
Spec1.02q Use intersection points: of graphs to solve equations1.08f Area between two curves: using integration

  1. Find the coordinates of the points where the curve and line intersect.
  2. Find the area of the shaded region bounded by the curve and line.

AnswerMarks Guidance
(a) \(2x^2 + 6x + 7 = 2x + 13\)M1
\(x^2 + 2x - 3 = 0\)M1
\((x+3)(x-1) = 0\)A1
\(x = -3, 1\)A1
\(\therefore (-3, 7), (1, 15)\)A1
(b) \(\text{area under curve} = \int_{-3}^{1} (2x^2 + 6x + 7) \, dx\)M1
\(= [\frac{2}{3}x^3 + 3x^2 + 7x]_{-3}^{1}\)M1 A2
\(= (\frac{2}{3} + 3 + 7) - (-18 + 27 - 21) = 22\frac{2}{3}\)M1
\(\text{area of trapezium} = \frac{1}{2} \times (7 + 15) \times 4 = 44\)B1
\(\text{shaded area} = 44 - 22\frac{2}{3} = 21\frac{1}{3}\)M1 A1 (11)
(a) $2x^2 + 6x + 7 = 2x + 13$ | M1 |

$x^2 + 2x - 3 = 0$ | M1 |

$(x+3)(x-1) = 0$ | A1 |

$x = -3, 1$ | A1 |

$\therefore (-3, 7), (1, 15)$ | A1 |

(b) $\text{area under curve} = \int_{-3}^{1} (2x^2 + 6x + 7) \, dx$ | M1 |

$= [\frac{2}{3}x^3 + 3x^2 + 7x]_{-3}^{1}$ | M1 A2 |

$= (\frac{2}{3} + 3 + 7) - (-18 + 27 - 21) = 22\frac{2}{3}$ | M1 |

$\text{area of trapezium} = \frac{1}{2} \times (7 + 15) \times 4 = 44$ | B1 |

$\text{shaded area} = 44 - 22\frac{2}{3} = 21\frac{1}{3}$ | M1 A1 | (11)
\begin{enumerate}[label=(\alph*)]
\item Find the coordinates of the points where the curve and line intersect.
\item Find the area of the shaded region bounded by the curve and line.
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2  Q7 [11]}}