Factor theorem
What Factor theorem means in Mathematics A-Level, as defined for AQA, Pearson Edexcel, WJEC.
Definitions of Factor theorem
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Reference: WJEC
A polynomial f(x) has a linear factor (x − a) if and only if f(a) = 0; more generally, (bx − a) is a factor if and only if f(a/b) = 0.
States that (x − a) is a factor of f(x) exactly when f(a) = 0, which allows you to find unknown constants and factorise cubics.
States that (x − a) is a factor of f(x) exactly when f(a) = 0, so substituting a candidate value tests for a factor.
Topics that use Factor theorem
- B: Algebra and functions (AQA A-Level)
- Algebra and functions (Pearson Edexcel A-Level)
- Algebra and Functions (AS Unit 1: Pure Mathematics A) (WJEC A-Level)
Related terms
- Completing the square
- Discriminant
- Asymptote
- Asymptotes
- Composite function
- Conjugate
- critical values
- direct proportion
Using Factor theorem in the exam
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