CAIE Further Paper 2 2021 November — Question 1 5 marks

Exam BoardCAIE
ModuleFurther Paper 2 (Further Paper 2)
Year2021
SessionNovember
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTaylor series
TypeUse series to approximate integral
DifficultyStandard +0.3 This is a straightforward application of standard Maclaurin series for sinh and cosh with simple substitution (x²), followed by routine differentiation coefficient extraction and polynomial integration. All steps are mechanical with no problem-solving insight required, though it's slightly above average difficulty due to being Further Maths content.
Spec4.07a Hyperbolic definitions: sinh, cosh, tanh as exponentials4.08a Maclaurin series: find series for function4.08b Standard Maclaurin series: e^x, sin, cos, ln(1+x), (1+x)^n

It is given that \(y = \sinh(x^2) + \cosh(x^2)\).
  1. Use standard results from the list of formulae (MF19) to find the Maclaurin's series for \(y\) in terms of \(x\) up to and including the term in \(x^4\). [2]
  2. Deduce the value of \(\frac{d^4y}{dx^4}\) when \(x = 0\). [1]
  3. Use your answer to part (a) to find an approximation to \(\int_0^{\frac{1}{2}} y \, dx\), giving your answer as a rational fraction in its lowest terms. [2]

Question 1:

AnswerMarks Guidance
1(a)( ) ( )
sinh x2 +cosh x2M1 Combines using correct power series. Or sensible
attempt at all four derivatives of y.
1+x2 +1x4
AnswerMarks
2A1
2

AnswerMarks
1(b)1×4!=12
2B1
1

AnswerMarks
1(c)1
21+x2 + 1x4 dx
2
AnswerMarks Guidance
0M1 Substitutes their power series, must be at least a+bx2.
1
=x+1x3 + 1 x52 = 523
AnswerMarks
 3 10  0 960A1
2
AnswerMarks Guidance
QuestionAnswer Marks
Question 1:
--- 1(a) ---
1(a) | ( ) ( )
sinh x2 +cosh x2 | M1 | Combines using correct power series. Or sensible
attempt at all four derivatives of y.
1+x2 +1x4
2 | A1
2
--- 1(b) ---
1(b) | 1×4!=12
2 | B1
1
--- 1(c) ---
1(c) | 1
21+x2 + 1x4 dx
2
0 | M1 | Substitutes their power series, must be at least a+bx2.
1
=x+1x3 + 1 x52 = 523
 3 10  0 960 | A1
2
Question | Answer | Marks | Guidance
It is given that $y = \sinh(x^2) + \cosh(x^2)$.

\begin{enumerate}[label=(\alph*)]
\item Use standard results from the list of formulae (MF19) to find the Maclaurin's series for $y$ in terms of $x$ up to and including the term in $x^4$. [2]

\item Deduce the value of $\frac{d^4y}{dx^4}$ when $x = 0$. [1]

\item Use your answer to part (a) to find an approximation to $\int_0^{\frac{1}{2}} y \, dx$, giving your answer as a rational fraction in its lowest terms. [2]
\end{enumerate}

\hfill \mbox{\textit{CAIE Further Paper 2 2021 Q1 [5]}}