Formulas Flashcards
Area of a Parallelogram
A = bh
Area of a Trapezoid
A = (b1+b2/2) x h
Sum of interior angles of any sided shape
Average degrees per side
n-2 (180º)
n = the number of sides
=180 (n-2) / n
Height of an Equilateral Triangle
h = 1/2 s√3
s = side
Area of a Circle
A = πr^2
Circumference of a Circle
A = 2πr
Arch Length of a Circle
Arch length = Circumference x Central Angle / 360º
The volume of a Cylinder
V = πr^2h
Slope Coordinates
m = (y2 - y1) / (x2 - x1)
Distance Between Points on a Graph
d = √ (x2 - x1)^2 + (y2 - y1)^2
Percent Change
percent change = (difference / original) x 100
Difference = new-original
Rates: Distance
Distance = Rate x Time
D = RT
Rates: Average Speed
Average Speed = Total Distance / Total Time
V=D/T
Rates: Work
Work = (individual rate) (number of workers) (time)
W = RT
Parabola Formula Normal
y = ax^2 + bx + c
1) Parabola Vetex Form
2) Coordinate location of the vertex
y = a (x-h)^2 + k
Vertex = h, k
Overlapping Sets
Total = Grp 1 + Grp 2 - Both + Neither
Simple Interest
V = P ( 1 + [rt/100] )
P = principle R = rate t = time
Compound Interest
V = P ( 1 + [r/100n ] )^nt
P = principle R = rate t = time n = number of compounds per year
Sequences
1+2+3+4+….n
= n (n+1) / 2
Standard Deviation
s = √ ∑(x-m)^2/n
Combinations
When the order does not matter – for example, picking any 3 friends from a group of 5.
nCr = n! / [ r! (n-r)! ]
n represents the number of items, and r represents the number of items being chosen at a time.
Permutations
When the order does matter – for example, how many ways you could order 3 letters from the word PARTY?
nPr = n! / (n-r)!
n represents the number of items, and r represents the number of items being chosen at a time.
