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SQA National 5 Mathematics

National 5 Mathematics formula reference

Quick reference cards for common National 5 Mathematics rules, formulae and method choices.

Laws of indices

am x an = am+n

= am−n

(am)n = amn

a^ = nth root of am

Surds

√(ab) = √a√b

=

Straight lines

m =

y − b = m(x − a)

y = mx + c

Quadratic formula

Quadratic formula

x =-b ± √(b² − 4ac)2a

x =

Discriminant

D = b² − 4ac

D > 0: two real and distinct roots

D = 0: one repeated real root

D < 0: no real roots

Pythagoras

a² + b² = c²

Volume of standard solids

V = πr³

V = πr² h

V = x base area x perpendicular height

Arc length and sector area

arc length = angle/360 × 2πr

sector area = angle/360 x πr²

Similarity

length factor = k

area factor = k²

volume factor = k³

Right-angled trigonometry

sin x = opposite ÷ hypotenuse

cos x = adjacent ÷ hypotenuse

tan x = opposite ÷ adjacent

Trigonometric identities

sin² x + cos² x = 1

tan x =

Area of a triangle using sine

Area = ab sin C

Sine rule

= =

Cosine rule

a² = b² + c² − 2bc cos A

cos A =

Vectors

AB = b − a

|(x, y)| = √(x² + y²)

|(x, y, z)| = √(x² + y² + z²)

Interquartile range

IQR = Q3 − Q1