## Exam Style Question## Worked solutions to typical exam type questions that you can reveal gradually |

Question id: 119. This question is similar to one that appeared in a IGCSE Extended paper in 2014. The use of a calculator is allowed.

If \(f(x)=5-4x\) and \(g(x)=4^{-x}\) then:

(a) Find \(f(3x)\) in terms of \(x\).

(b) Find \(ff(x)\) in its simplest form.

(c) Work out \(gg(–1)\) give your answer as a fraction.

(d) Find \(f^{–1}(x)\), the inverse of \(f(x)\).

(e) Solve the equation \(gf(x)= 1\).

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