CAIE P1 2011 June — Question 4 7 marks

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2011
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicProduct & Quotient Rules
TypeFind derivative of quotient
DifficultyEasy -1.2 Part (a) is a straightforward quotient differentiation that can be simplified to 2x² + 5x⁻¹ before differentiating, avoiding the quotient rule entirely. Part (b) is a standard chain rule integration (reverse) followed by definite integral evaluation. Both parts require only routine application of basic calculus techniques with no problem-solving or insight needed.
Spec1.07i Differentiate x^n: for rational n and sums1.08b Integrate x^n: where n != -1 and sums1.08d Evaluate definite integrals: between limits

4
  1. Differentiate \(\frac { 2 x ^ { 3 } + 5 } { x }\) with respect to \(x\).
  2. Find \(\int ( 3 x - 2 ) ^ { 5 } \mathrm {~d} x\) and hence find the value of \(\int _ { 0 } ^ { 1 } ( 3 x - 2 ) ^ { 5 } \mathrm {~d} x\).

AnswerMarks Guidance
(a) \(y = \frac{2x^3 + 5}{x} = 2x^2 + \frac{5}{x}\)M1 Knows to divide numerator by \(x\)
\(\frac{dy}{dx} = 4x - \frac{5}{x^2}\) or \(4x - 5x^{-2}\)A1 + A1 co
[3]
(b) \(\int(3x-2)^5 dx = \frac{(3x-2)^6}{6} \cdot 3 \, (+c)\)B1 B1 B1 without "\(\cdot 3\)". B1 for "\(\cdot 3\)". (ignore (+c))
\(\int_0^{} (3x-2)^5 dx = \left[\frac{(3x-2)^6}{18}\right]\)M1 Uses limits after integration.
Limits used correctly \(\rightarrow -3\frac{1}{2}\)A1 co
[4]
(a) $y = \frac{2x^3 + 5}{x} = 2x^2 + \frac{5}{x}$ | M1 | Knows to divide numerator by $x$
$\frac{dy}{dx} = 4x - \frac{5}{x^2}$ or $4x - 5x^{-2}$ | A1 + A1 | co
| [3] |

(b) $\int(3x-2)^5 dx = \frac{(3x-2)^6}{6} \cdot 3 \, (+c)$ | B1 B1 | B1 without "$\cdot 3$". B1 for "$\cdot 3$". (ignore (+c))
$\int_0^{} (3x-2)^5 dx = \left[\frac{(3x-2)^6}{18}\right]$ | M1 | Uses limits after integration.
Limits used correctly $\rightarrow -3\frac{1}{2}$ | A1 | co
| [4] |
4
\begin{enumerate}[label=(\alph*)]
\item Differentiate $\frac { 2 x ^ { 3 } + 5 } { x }$ with respect to $x$.
\item Find $\int ( 3 x - 2 ) ^ { 5 } \mathrm {~d} x$ and hence find the value of $\int _ { 0 } ^ { 1 } ( 3 x - 2 ) ^ { 5 } \mathrm {~d} x$.
\end{enumerate}

\hfill \mbox{\textit{CAIE P1 2011 Q4 [7]}}