OCR MEI C2 2011 June — Question 8 3 marks

Exam BoardOCR MEI
ModuleC2 (Core Mathematics 2)
Year2011
SessionJune
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicExponential Equations & Modelling
TypeInverse function with exponentials
DifficultyEasy -1.2 This is a straightforward logarithm manipulation question requiring only two steps: take logarithms of both sides and rearrange. It's a standard textbook exercise testing basic log laws with no problem-solving element, making it easier than average for A-level.
Spec1.06f Laws of logarithms: addition, subtraction, power rules

8 Using logarithms, rearrange \(p = s t ^ { n }\) to make \(n\) the subject.

AnswerMarks Guidance
\(\log p = \log s + \log t^n\)M1 or \(\frac{p}{s} = t^n\)
\(\log p = \log s + n \log t\)M1 \(n \log t = \log\left(\frac{p}{s}\right)\)
\([n =] \frac{\log p - \log s}{\log t}\) or \(\frac{\log\left(\frac{p}{s}\right)}{\log t}\) [base not required]A1 or A2 for \([n =]\log_t\left(\frac{p}{s}\right)\) [base t needed] following first M1; as final answer (i.e. penalise further incorrect simplification)
$\log p = \log s + \log t^n$ | M1 | or $\frac{p}{s} = t^n$
$\log p = \log s + n \log t$ | M1 | $n \log t = \log\left(\frac{p}{s}\right)$
$[n =] \frac{\log p - \log s}{\log t}$ or $\frac{\log\left(\frac{p}{s}\right)}{\log t}$ [base not required] | A1 | or A2 for $[n =]\log_t\left(\frac{p}{s}\right)$ [base t needed] following first M1; as final answer (i.e. penalise further incorrect simplification)
8 Using logarithms, rearrange $p = s t ^ { n }$ to make $n$ the subject.

\hfill \mbox{\textit{OCR MEI C2 2011 Q8 [3]}}