The functions f f\,f and g g\,g are defined for all real values of x x\,x by
f(x)=x3andg(x)=x2−1 f(x) = x^3 \quad \text{and} \quad g(x) = x^2 - 1 f(x)=x3andg(x)=x2−1Write down expressions for fg(x)fg(x)fg(x) and gf(x)gf(x)gf(x)
Hence find the value of gf(x)−fg(x)gf(x) - fg(x)gf(x)−fg(x) when x=±3x = \pm \sqrt{3}x=±3
471 exam-style questions on Edexcel A Level Maths Functions and Graphs, covering 2.1 The Modulus Function, 2.2 Functions and Mappings, 2.3 Composite Functions, 2.4 Inverse Functions, 2.5 y=|f(x)| and y=f(|x|), 2.6 Combining Transformations, and 2.7 Solving Modulus Problems. Each one has a worked solution and a mark scheme showing where the marks go.