Skip to main content

Back to the full dot-point answer

WalesMathsQuick questions

A2 Unit 3 Pure Mathematics B

Quick questions on Functions: modulus, composite, inverse and partial fractions - WJEC A-Level Maths

7short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is the modulus function?
Show answer
The modulus (or absolute value) x|x| equals xx when x0x \ge 0 and x-x when x<0x < 0, so it is never negative.
What are composite functions?
Show answer
A composite function applies one function then another. The notation fg(x)fg(x) means "do gg first, then ff": fg(x)=f(g(x))fg(x) = f(g(x)).
What are inverse functions?
Show answer
The inverse f1f^{-1} undoes ff, so f1(f(x))=xf^{-1}(f(x)) = x. It exists only if ff is one-to-one (each output comes from exactly one input).
What are partial fractions?
Show answer
A proper rational expression (degree of numerator below degree of denominator) splits into a sum with one fraction per factor of the denominator.
What is q1?
Show answer
Solve x2=6|x - 2| = 6. [2 marks]
What is q2?
Show answer
Given f(x)=x2f(x) = x^2 and g(x)=x+1g(x) = x + 1, find fg(x)fg(x). [2 marks]
What is q3?
Show answer
Find the inverse of f(x)=1x2f(x) = \dfrac{1}{x - 2}, x2x \neq 2. [3 marks]

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All MathsQ&A pages