Edexcel IGCSE Mathematics A (4MA1) Essential Formulae

Percentage Change

(change / original ) x 100

Compound Interest / Growth

Total = P x (1 + r / 100) ⁿ

Area of triangle

½ x base x height

Area of a Parallelogram

Area of Circle

πr²

Circumference of Cicle

2πr / πd

Arc Length

(θ / 360 ) x πr²

Arc of a Sector

(θ / 360) x πr²

Pythagoras Theorem

SOH CAH TOA

• sin(θ) = Opposite / Hypotenuse

• cos(θ) = Adjacent / Hypotenuse

• tan(θ) = Opposite / Adjacent

Gradient

m = (y₂- y₁) / (x₂ - x₁)

Equation of a straight line

y = mx + c

Midpoint

• ((x₁+ x₂) / 2

• (y₁ + y₂) / 2)

Distance Between Two Points

d = √((x₂ - x₁)2 + (y₂ - y₁)²)

Perpendicular Lines Gradient

m₁ x m₂ = -1

Speed

Distance / Time

Density

Mass / Volume

Pressure

Force / Area

Sum of Interior Angles

(n-2) x 180^.

Exterior Angle of Regular Polygon

360° / n

Interior Angle + Exterior Angle

= 180°

nth Term of Arithmetic Sequence

a_n = a + (n - 1)d

Difference of Two Squares

a² - b² = (a + b)(a - b)

Probability of Event: P(A)

Number of successful outcomes / Total number of possible outcomes

Complementary Event

P(not A) = 1 - P(A)

Mutually Exclusive Events

P(A or B) = P(A) + P(B)

· Independent Events

P(A and B) = P(A) × P(B)

· Conditional Probability [Higher Only]: P(A and B) = P(A) × P(B | A)

P(A and B) = P(A) × P(B | A)

· Frequency Density (Histograms) [Higher Only]

Frequency Density = Frequency / Class Width