Edexcel IGCSE·Mathematics 4MA1
Index Laws
Key knowledge — Algebra
Formulas & equations
Quadratic formula: x = (−b ± √(b²−4ac)) ÷ 2aDifference of two squares: a² − b² = (a+b)(a−b)Completing the square: ax² + bx + c = a(x + b/2a)² + (c − b²/4a)Sum of arithmetic sequence: Sₙ = n/2 × (first + last) = n/2 × (2a + (n−1)d)nth term of AP: aₙ = a + (n−1)dnth term of GP: aₙ = arⁿ⁻¹
Key facts & rules
- To solve a quadratic: factorise, complete the square, or use the formula.
- To solve simultaneous equations: elimination (add/subtract to remove one variable) or substitution.
- Inequalities: flip the sign when multiplying or dividing by a negative number.
- Algebraic fractions: find common denominator, then add/subtract numerators.
- Direct proportion: y = kx. Inverse proportion: y = k/x.
Laws & theorems
- Factor theorem: if (x − a) is a factor of f(x), then f(a) = 0.
Index laws
18 Edexcel IGCSE 4MA1 past paper questions on index laws — Foundation and Higher, with mark schemes.
Question 1 of 18
Show mark scheme
Question 2 of 18
Show mark scheme
Question 3 of 18
Show mark scheme
Question 4 of 18
Show mark scheme
Question 5 of 18
Show mark scheme
Question 6 of 18
Show mark scheme
Question 7 of 18
Show mark scheme
Question 8 of 18
Show mark scheme
Question 9 of 18
Show mark scheme
Question 10 of 18
Show mark scheme
Question 11 of 18
Show mark scheme
Question 12 of 18
Show mark scheme
Question 13 of 18
Show mark scheme
Question 14 of 18
Show mark scheme
Question 15 of 18
Show mark scheme
Question 16 of 18
Show mark scheme
Question 17 of 18
Show mark scheme
Question 18 of 18
Show mark scheme
