SPS SPS FM Pure 2023 November — Question 5 6 marks

Exam BoardSPS
ModuleSPS FM Pure (SPS FM Pure)
Year2023
SessionNovember
Marks6
TopicTaylor series
TypeUse series to find error or validity
DifficultyModerate -0.3 This is a straightforward application of standard Maclaurin series. Part (a) requires recall of ln(1+x) series and substitution. Part (b) is routine percentage error calculation. Part (c) tests understanding of radius of convergence (x=1 is outside |2x|<1), which is a standard conceptual check. The question is slightly easier than average due to being mostly procedural with minimal problem-solving required.
Spec4.08a Maclaurin series: find series for function4.08b Standard Maclaurin series: e^x, sin, cos, ln(1+x), (1+x)^n

  1. Use a Maclaurin series to find a quadratic approximation for \(\ln(1 + 2x)\). [1]
  2. Find the percentage error in using the approximation in part (a) to calculate \(\ln(1.2)\). [3]
  3. Jane uses the Maclaurin series in part (a) to try to calculate an approximation for \(\ln 3\). Explain whether her method is valid. [2]

(a) Use a Maclaurin series to find a quadratic approximation for $\ln(1 + 2x)$. [1]

(b) Find the percentage error in using the approximation in part (a) to calculate $\ln(1.2)$. [3]

(c) Jane uses the Maclaurin series in part (a) to try to calculate an approximation for $\ln 3$.

Explain whether her method is valid. [2]

\hfill \mbox{\textit{SPS SPS FM Pure 2023 Q5 [6]}}