The function f f\,f is defined by f(x)=(x−4)2−7f(x) = (x - 4)^2 - 7f(x)=(x−4)2−7 for x≥4x \geq 4x≥4. The solution to the equation f(x)=xf(x)=xf(x)=x is 9+352\displaystyle \frac{9+3\sqrt{5}}{2}29+35.
Explain why your answer to part (c) is also the solution to the equation f(x)=f−1(x)f(x) = f^{-1}(x)f(x)=f−1(x)
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.