CAIE IGCSE Mathematics Extended E2.13.3 Form Composite Functions As Defined By Gf X G F X Questions

Practise Extended CAIE IGCSE Mathematics by composing function rules, simplifying results and checking composition order.

Exam points

Form composite functions using gf(x) = g(f(x)) and related notation.
Evaluate and simplify composite functions from given function rules or mappings.
Interpret the order of composition and distinguish fg(x) from gf(x).

[Maximum number: 3]

\mathrm{f}(x)=5^{x} \quad \mathrm{~g}(x)=3 x-2 \quad \mathrm{~h}(x)=x^{2}+1

Find the positive solution of gh(x)=364.

11

M2 for $3 x^{2}+1=364$ or better or M1 for $3\left(x^{2}+1\right)-2$

Alternative method:

M2 for $x^{2}+1=(364+2) \div 3$ or M1 for 3 x-2=364

All question bank results loaded