AQA FP1 2007 June — Question 5

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2007
SessionJune
TopicExponential Equations & Modelling

5 [Figure 1 and Figure 2, printed on the insert, are provided for use in this question.] The variables \(x\) and \(y\) are known to be related by an equation of the form $$y = a b ^ { x }$$ where \(a\) and \(b\) are constants. The following approximate values of \(x\) and \(y\) have been found.
\(x\)1234
\(y\)3.846.149.8215.7
  1. Complete the table in Figure 1, showing values of \(x\) and \(Y\), where \(Y = \log _ { 10 } y\). Give each value of \(Y\) to three decimal places.
  2. Show that, if \(y = a b ^ { x }\), then \(x\) and \(Y\) must satisfy an equation of the form $$Y = m x + c$$
  3. Draw on Figure 2 a linear graph relating \(x\) and \(Y\).
  4. Hence find estimates for the values of \(a\) and \(b\).