Maths Formula Flashcards
Area of a trapezium
A = 1/2 ( a + b) h
Volume of prism
area of cross section x depth
exterior angle formulae
exterior angle = 360°/ n
n = Number of angles
sum of interior angles in a n-sided polygon
sum of interior angles = ( n - 2 ) x 180°
n = Number of angles
Percentage increase
Percentage increase = (new amount - original / original amount) x 100
Percentage decrease
Percentage decrease = (actual decrease / original amount) x 100
Volume of a pyramid
1/3 x area of base x h
Percentage profit
Percentage profit = (profit / cost price) x 100
Percentage loss
Percentage loss = (loss / cost price) x 100
Simple interest
I = (P x R x T) / 100
I = Simple interest
P = Principal
R = Rate
T = Time or duration
Surface area of a sphere
SA = 4πr^2
SA = Surface Area
^2 = Squared
Volume of a sphere
V = 4/3πr
V = Volume
r = Radius
Surface area to volume ratio
SA:V = surface area / volume
SA = Surface Area
V = Volume
Trigonometric ratios
(SOH) sin x° = o/h
(CAH) cos x° = a/h
(TOA) tan x° = o/a
o = Opposite (to the right angle)
a = Adjacent (to the right angle)
h = Hypotenuse (longest side)
Area of a parallelogram
A = b x h
A = Area
B = Base
H = Height
Quadratic Forumula
x = (-b ±√b^2 - 4ac) / 2a
± = + or -
√ = Square Root
A quadratic equation is a second order equation written as ax2 + bx + c = 0 where a, b, and c are coefficients of real numbers and a ≠ 0.
Pythagoras Theorem (Right angled triangles)
a^2 + b^2 = c^2
c^2 - a^2 = b^2
c^2 - b^2 = a^2
a or b = Lines adjacent to right angle
c = Hypotenuse
^2 = Squared
Sine rule
a/Sin A = b/sin B = c/Sin C
Area of circle
A = πr^2
A = Area
r = Radius
^2 = Squared
Volume of a cone
V = 1/3πr^2h
V = Volume
r = Radius
^2 = Squared
h = Height
Standard deviation
σ = sqrt( Σ (X - x̄)2 / n-1)
Σ = summation
x̄ = mean of data set
X = data point
n = amount of data points
Angle in degrees of a linear function relative to the x-axis
θ = tan-1(m) * 180 / π
m = gradient
