2020 ACJC Promo Q7

Timothy Gan

2020 ACJC Promo Q7

The functions $\text{f}$ and $\text{g}$ are defined as follows:

$\text{f}:x\mapsto 7{{\left( x-a \right)}^{2}}-1$, $x\in \mathbb{R}$, $x<3$
$\text{g}:x\mapsto 1+b-{{e}^{-x}}$, $x\ge 0$,

where $a$ and $b$ are real constants.

(i)

State the smallest value of $a$ such that ${{\text{f}}^{-1}}$ exists.

For the rest of this question, $a=4$.

(ii)

Explain if ${{\text{f}}^{-1}}$ exists, and if it does, find ${{\text{f}}^{-1}}\left( x \right)$ and state its domain.

(iii)

Find the largest value of $b$ such that the composite function $\text{fg}$ exists.
For this value of $b$, find $\text{fg}\left( x \right)$, state its domain, and find its range.

Suggested Video Solutions

Students Only

Login here to view
Join Us

Our H2 Math Tuition includes

  • Question Bank with Video solutions to 1400+ questions
  • Online Portal
  • H2 Math Summary Notes
  • Structured Curriculum and Notes
Free Stuff

Share with your friends!

WhatsApp
Telegram
Facebook
Continue reading
MF 27 for H2 Math Tuition
List MF 27

What is the MF 27? The MF 27, set to replace the MF 26 from 2025, is a comprehensive formula sheet developed by the Ministry of Education Singapore in collaboration

Read More

Published: 1st April 2024

Written by

Timothy Gan

This is Tim. Tim loves to teach math. Tim seeks to improve his teaching incessantly! Help Tim by telling him how he can do better.

Leave a Reply

Your email address will not be published. Required fields are marked *