DAY 3 FORMULA Flashcards
measure of an interior angle of a regular polygon
180 (n-2) /2
number of diagonals of a polygon
n(n-3)/2 or nC2-n
apothem
angle = 180/n
perimeter of regular polygon
P=nx
Area of a regular polygon
Apolygon = n x Atriangle
Atriangle = (1/2) x ax
area of trapezoid
[ (b1+b2) x h ] / 2
angle between two lines
tan@ = abs |(m2-m1)/(1+m2m1)|
binomial theorem expansion
nCr (a)^n-r (b)^r where r=nth term - 1
clock problem formula
angle = |30h - 5.5m|
x = (60/11) (initial + hr spaces)
workers & working time
constant = # workers x total time / # of units (1 default)
upstream & downstream
downstream:
(rboat + rcurrent) = d/t down
upstream
(rboat - rcurrent) = d/t up
td + tu = 1
area of a sector
A = 1/2 r^2 theta = Lr/2
L = r theta
volume of a cylinder
V = pi r^2 h
volume of a cone
V = pi r^2 h/3
volume of a sphere
V = 4 pi r^3 / 3
lateral area of cylinder
2 pi r L
surface area of cylinder
2 pi r^2 + 2 pi r L
lateral area of cone
pi r L
surface area of cone
pi r L + pi r^2
surface area of sphere
4 pi r^2
poisson’s distribution
P = e^-lambda x lambda^n / n!
interquartile and semiIQR
IQR = Q3-Q1 semi = Q3-Q1/2
odds (happening)
P/1-P
odds (not happening)
1-P/P
area of quadrilateral
A = 1/2 (sume of lower - sum of upper)
effective rate of interest
ERI = (1+r/m)^m - 1
compound interest
F = P (1+r/m)^mt
continuously compounding
F = Pe^rn