The function f f\,f is defined by
f(x)=5x−17x−4,x∈R,x≠4 f(x) = \frac{5x - 17}{x - 4}, \quad x \in \mathbb{R}, x \neq 4 f(x)=x−45x−17,x∈R,x=4Find f−1(6)f^{-1}(6)f−1(6)
Show that ff(x)=ax+bx−1\displaystyle ff(x) = \frac{ax + b}{x - 1}ff(x)=x−1ax+b where a a\,a and b b\,b are integers to be found.
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.