OCR C2 2013 June — Question 8

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Year2013
SessionJune
TopicExponential Functions

8
\includegraphics[max width=\textwidth, alt={}, center]{b2c1188d-881e-4fb5-bece-5a51006543c7-4_524_822_274_609} The diagram shows the curves \(y = a ^ { x }\) and \(y = 4 b ^ { x }\).
  1. (a) State the coordinates of the point of intersection of \(y = a ^ { x }\) with the \(y\)-axis.
    (b) State the coordinates of the point of intersection of \(y = 4 b ^ { x }\) with the \(y\)-axis.
    (c) State a possible value for \(a\) and a possible value for \(b\).
  2. It is now given that \(a b = 2\). Show that the \(x\)-coordinate of the point of intersection of \(y = a ^ { x }\) and \(y = 4 b ^ { x }\) can be written as $$x = \frac { 2 } { 2 \log _ { 2 } a - 1 } .$$