Edexcel C3 — Question 5

Exam BoardEdexcel
ModuleC3 (Core Mathematics 3)
TopicComposite & Inverse Functions

  1. The function f is given by
$$\mathrm { f } : x \mapsto \frac { x } { x ^ { 2 } - 1 } - \frac { 1 } { x + 1 } , x > 1 .$$
  1. Show that \(\mathrm { f } ( x ) = \frac { 1 } { ( x - 1 ) ( x + 1 ) }\).
  2. Find the range of f. The function g is given by $$\mathrm { g } : x \mapsto \frac { 2 } { x } , \quad x > 0 .$$
  3. Solve \(\operatorname { gf } ( x ) = 70\).