WJEC Unit 3 2024 June — Question 10 4 marks

Exam BoardWJEC
ModuleUnit 3 (Unit 3)
Year2024
SessionJune
Marks4
TopicComposite & Inverse Functions

10. The function \(f\) has domain \([ 4 , \infty )\) and is defined by $$f ( x ) = \frac { 2 ( 3 x + 1 ) } { x ^ { 2 } - 2 x - 3 } + \frac { x } { x + 1 }$$
  1. Show that \(f ( x ) = \frac { x + 2 } { x - 3 }\).
    10. The function \(f\) has domain \([ 4 , \infty )\) and is defined by $$f ( x ) = \frac { 2 ( 3 x + 1 ) } { x ^ { 2 } - 2 x - 3 } + \frac { x } { x + 1 } .$$
  2. Show that \(f ( x ) = \frac { x + 2 } { x - 3 }\). [4]
  3. Determine the range of \(f ( x )\).
  4. Find an expression for \(f ^ { - 1 } ( x )\) and write down the domain and range of \(f ^ { - 1 }\).
  5. Find the value of \(x\) when \(f ( x ) = f ^ { - 1 } ( x )\).