The functions f f\,f and g g\,g are defined for all real values of x x\,x by
f(x)=x3f(x) = x^3f(x)=x3 and g(x)=x2−1g(x) = x^2 - 1g(x)=x2−1
Write down expressions for fg(x)fg(x)fg(x) and gf(x)gf(x)gf(x).
Hence find the values of x x\,x for which gf(x)−fg(x)=18gf(x) - fg(x) = 18gf(x)−fg(x)=18.
216 exam-style questions on WJEC A Level Maths 3.2 Algebra and Functions (A-level only), covering 3.2.1 Algebra and Functions (A-level only), 3.2.2 Algebra and Functions (A-level only), 3.2.3 Algebra and Functions (A-level only), 3.2.4 Algebra and Functions (A-level only), 3.2.5 Algebra and Functions (A-level only), 3.2.6 Algebra and Functions (A-level only), and 3.2 Algebra and Functions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.