OCR MEI C2 — Question 1 13 marks

Exam BoardOCR MEI
ModuleC2 (Core Mathematics 2)
Marks13
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTangents, normals and gradients
TypeFind tangent at given point (polynomial/algebraic)
DifficultyModerate -0.3 This is a straightforward multi-part calculus question covering standard C2 techniques: differentiation (power rule), tangent equations (point-slope form), verifying roots by substitution, and definite integration. All parts are routine applications with no problem-solving insight required, though the integration in part (iv) requires careful handling of the sign to find area below the axis. Slightly easier than average due to the guided structure and standard methods.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.07i Differentiate x^n: for rational n and sums1.07m Tangents and normals: gradient and equations1.08e Area between curve and x-axis: using definite integrals

\includegraphics{figure_1} Fig. 9 shows a sketch of the graph of \(y = x^3 - 10x^2 + 12x + 72\).
  1. Write down \(\frac{dy}{dx}\). [2]
  2. Find the equation of the tangent to the curve at the point on the curve where \(x = 2\). [4]
  3. Show that the curve crosses the \(x\)-axis at \(x = -2\). Show also that the curve touches the \(x\)-axis at \(x = 6\). [3]
  4. Find the area of the finite region bounded by the curve and the \(x\)-axis, shown shaded in Fig. 9. [4]

Question 1:
AnswerMarks
1i
ii
iii
AnswerMarks
iv3x2 − 20x + 12
y − 64 = −16(x − 2) o.e.
eg y = −16x + 96
Factorising f(x) ≡(x+2)(x−6)2
OR Expanding (x+2)(x−6)2
x4 10x3
− +6x2 +72x
4 3
value at (x = 6) ~ value at (x = −2)
AnswerMarks
341(.3..) cao2
4
B3
M2
E1
B2
M1
AnswerMarks
A1B1 if one error “+c” is an error
M1 for subst x = 2 in their y′
A1 for y′ = −16 and B1 for y = 64
or B1 for f(-2) = -8-40-24+72 =0 and
B1 for f ′(6) = 0 and
B1dep for f(6)=0
-1 for each error
AnswerMarks
Must have integrated f(x)2
4
3
4
Question 1:
1 | i
ii
iii
iv | 3x2 − 20x + 12
y − 64 = −16(x − 2) o.e.
eg y = −16x + 96
Factorising f(x) ≡(x+2)(x−6)2
OR Expanding (x+2)(x−6)2
x4 10x3
− +6x2 +72x
4 3
value at (x = 6) ~ value at (x = −2)
341(.3..) cao | 2
4
B3
M2
E1
B2
M1
A1 | B1 if one error “+c” is an error
M1 for subst x = 2 in their y′
A1 for y′ = −16 and B1 for y = 64
or B1 for f(-2) = -8-40-24+72 =0 and
B1 for f ′(6) = 0 and
B1dep for f(6)=0
-1 for each error
Must have integrated f(x) | 2
4
3
4
\includegraphics{figure_1}

Fig. 9 shows a sketch of the graph of $y = x^3 - 10x^2 + 12x + 72$.

\begin{enumerate}[label=(\roman*)]
\item Write down $\frac{dy}{dx}$. [2]

\item Find the equation of the tangent to the curve at the point on the curve where $x = 2$. [4]

\item Show that the curve crosses the $x$-axis at $x = -2$. Show also that the curve touches the $x$-axis at $x = 6$. [3]

\item Find the area of the finite region bounded by the curve and the $x$-axis, shown shaded in Fig. 9. [4]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C2  Q1 [13]}}