Moderate -0.5 This is a standard logarithmic transformation question requiring students to recognize that ln(y) = ln(A) + px - p gives a linear relationship, then use two points to find the gradient (p) and y-intercept to find A. It involves routine algebraic manipulation and substitution with no novel insight required, making it slightly easier than average.
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\includegraphics[max width=\textwidth, alt={}, center]{595e38f4-c52e-4509-8b16-f08e30dec96b-2_456_716_529_712}
The variables \(x\) and \(y\) satisfy the equation
$$y = A \mathrm { e } ^ { p ( x - 1 ) } ,$$
where \(A\) and \(p\) are constants. The graph of \(\ln y\) against \(x\) is a straight line passing through the points \(( 2,1.60 )\) and \(( 5,2.92 )\), as shown in the diagram. Find the values of \(A\) and \(p\) correct to 2 significant figures.
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\includegraphics[max width=\textwidth, alt={}, center]{595e38f4-c52e-4509-8b16-f08e30dec96b-2_456_716_529_712}
The variables $x$ and $y$ satisfy the equation
$$y = A \mathrm { e } ^ { p ( x - 1 ) } ,$$
where $A$ and $p$ are constants. The graph of $\ln y$ against $x$ is a straight line passing through the points $( 2,1.60 )$ and $( 5,2.92 )$, as shown in the diagram. Find the values of $A$ and $p$ correct to 2 significant figures.
\hfill \mbox{\textit{CAIE P2 2015 Q2 [5]}}