| Exam Board | Edexcel |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Exponential Functions |
| Type | Compound interest and percentage growth |
| Difficulty | Easy -1.2 This is a straightforward C2 exponential question requiring only routine techniques: sketching a standard exponential graph, direct substitution into the formula, and solving a basic logarithmic equation. All three parts are textbook exercises with no problem-solving or novel insight required, making it easier than average. |
| Spec | 1.06a Exponential function: a^x and e^x graphs and properties1.06g Equations with exponentials: solve a^x = b |
3. Every $\pounds 1$ of money invested in a savings scheme continuously gains interest at a rate of $4 \%$ per year. Hence, after $x$ years, the total value of an initial $\pounds 1$ investment is $\pounds y$, where
$$y = 1.04 ^ { x }$$
\begin{enumerate}[label=(\alph*)]
\item Sketch the graph of $y = 1.04 ^ { x } , x \geq 0$.
\item Calculate, to the nearest $\pounds$, the total value of an initial $\pounds 800$ investment after 10 years.
\item Use logarithms to find the number of years it takes to double the total value of any initial investment.
\end{enumerate}
\hfill \mbox{\textit{Edexcel C2 Q3 [7]}}