2016 HCI P1 Q11

2016 HCI P1 Q11

13 marks
Prelims

The functions \(\mathrm{f}\) and \(\mathrm{g}\) are defined by

\(\mathrm{f}:x\mapsto \frac{1}{2}{{e}^{1-{{x}^{2}}}},\mathrm{ }x\in \mathbb{R},\mathrm{ }x\le 1\)

\(\mathrm{g}:x\mapsto \sqrt{1-\ln x},\mathrm{ }x\in \mathbb{R},\mathrm{ }0 < x\le e\).

  1. Show that \(\mathrm{gf}\) exists, and find the range of \(\mathrm{gf}\).[4]
  2. Justify, with a reason, whether \({{\mathrm{f}}^{-1}}\) exists.[2]
  3. The domain of \(\mathrm{f}\) is restricted to \(\left( -\infty ,b \right]\) such that \(b\) is the largest value for which the inverse function \({{\mathrm{f}}^{-1}}\) exists. State the value of \(b\) and define \({{\mathrm{f}}^{-1}}\)clearly.[4]
  4. The graph of \(y=\mathrm{h}\left( x \right)\) is obtained by transforming the graph of \(y=\mathrm{g}(x)\) in the following \(2\) steps.
    Step 1: Scale parallel to the \(x\)-axis by a factor of \(2\).
    Step 2: Reflect in the \(x\)-axis.
    Define \(\mathrm{h}\) in a similar form.[3]

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:gf exists, R_gf = [√(ln2), ∞); f⁻¹ doesn't exist; b = 0, f⁻¹(x) = −√(1−ln(2x)); h(x) = −√(1−ln(x/2))

Need help? Join our JC Math tuition classes.

Learn more