Edexcel AS Paper 1 Specimen — Question 8

Exam BoardEdexcel
ModuleAS Paper 1 (AS Paper 1)
SessionSpecimen
TopicArea Under & Between Curves

8. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{fa7abe9f-f5c0-4578-afd1-73176c717536-16_607_983_255_541} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} Figure 2 shows a sketch of the curve with equation \(y = \sqrt { x } , x \geqslant 0\)
The region \(R\), shown shaded in Figure 2, is bounded by the curve, the line with equation \(x = 1\), the \(x\)-axis and the line with equation \(x = a\), where \(a\) is a constant. Given that the area of \(R\) is 10
  1. find, in simplest form, the value of
    1. \(\int _ { 1 } ^ { a } \sqrt { 8 x } \mathrm {~d} x\)
    2. \(\int _ { 0 } ^ { a } \sqrt { x } \mathrm {~d} x\)
  2. show that \(a = 2 ^ { k }\), where \(k\) is a rational constant to be found.