Polynomial
P(x) = aₙxⁿ + … + a₀ with aₙ ≠ 0. The degree is n.
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Lesson overview
This lesson brings together the PDF, study notes and chapter flow so you can revise Polynomials without losing the thread.
Polynomial
P(x) = aₙxⁿ + … + a₀ with aₙ ≠ 0. The degree is n.
Addition and subtraction
Add/subtract coefficients of the same degree.
Multiplication
deg(P·Q) = deg(P) + deg(Q). Expand term by term.
Euclidean division of polynomials
P = Q·D + R with deg(R) < deg(D). Q is the quotient, R the remainder.
Remainder theorem
The remainder of dividing P by (x − a) is P(a).
Factor theorem
a is a root of P ⟺ (x − a) divides P(x), i.e. P(a) = 0.
(a+b)²
(a+b)² = a² + 2ab + b²
(a−b)²
(a−b)² = a² − 2ab + b²
a²−b² (difference of squares)
a² − b² = (a−b)(a+b)
(a+b)³
(a+b)³ = a³ + 3a²b + 3ab² + b³
Problem-solving method
Identify data, set formulas, solve step by step, then verify sign, unit, and coherence.
Common mistakes
Forgetting domain constraints, mixing equality/equivalence, and losing solutions during transformations.