2016 JJC P1 Q6

2016 JJC P1 Q6

10 marks
Prelims

A function \(\mathrm{f}\) is said to be self-inverse if \(\mathrm{f}(x)={{\mathrm{f}}^{-1}}(x)\) for all \(x\) in the domain of \(\mathrm{f}\).

The function \(\mathrm{g}\) is defined by

\(\mathrm{g}:x\mapsto \sqrt{\frac{{{x}^{2}}+2}{{{x}^{2}}-1}},\mathrm{ }x>1\) .

  1. Sketch the curve \(y=\mathrm{g}\left( x \right)\) stating the equations of the asymptotes clearly.[2]
  2. Define \({{\mathrm{g}}^{-1}}\) in a similar form and show that \(\mathrm{g}\) is self-inverse.[4]
  3. Show that \({{\mathrm{g}}^{2}}(x)=x\) and that \({{\mathrm{g}}^{3}}(x)=\mathrm{g}(x)\) . Hence find the values of \(x\) for which \(4-{{\mathrm{g}}^{50}}(x)={{\left[ {{\mathrm{g}}^{51}}(x) \right]}^{2}}\).[4]

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs tuition enrolment.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:\(x = 2\) or \(x = \frac{1+\sqrt{13}}{2}\)

Need help? Join our JC Math tuition classes.

Learn more