The functions f f\,f and g g\,g are defined for all real values of x x\,x by
f(x)=2x2−kx and g(x)=4x+6 f(x) = 2x^2 - kx \text{ and } g(x) = 4x + 6 f(x)=2x2−kx and g(x)=4x+6Find the range of fff.
Give a reason why f f\,f has no inverse.
Given that gf(2)=g−1(a)gf(2) = g^{-1}(a)gf(2)=g−1(a), where a a\,a is a constant, determine the value of aaa.
Determine the set of values for which f(x)>g(x)f(x) > g(x)f(x)>g(x). Give your answer in set notation.
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.