Formulas Flashcards
sinA
opposite/hypotenuse
or
cos(90°-A)
cosA
adjacent/hypotenuse
or
sin(90°-A)
tanA
opposite/adjacent
cscA
hypotenuse/opposite
or
1/sinA
secA
hypotenuse/adjacent
or
1/cosA
cotA
adjacent/opposite
or
1/tanA
sin(-A)
-sinA
cos(-A)
cos(A)
sin2A
2sinAcosA
cos2A
cos2A-sin2A
pythagorean identities
sin2A + cos2A = 1
and
tan2A + 1 = sec2A
1-cos2A=
sin2A
sec2A-1=
tan2A
Area of a circle
Circumference
ArcLength
Asector
A = πr2
C = 2πr = π
ArcLength = (-) / 360 (2πr)
Asector = (-) / 360 (πr2)
Area of a sphere
Volume
A = 4 πr2
V = (4/3)πr3
Area of a cylinder
Volume
A = 2πrh
V = πr2h
Area of an Ellipse
πab
Area of a triangle
(1/2)b•h
Area of a rhombus
b•h
distance
= velocity • time
time
= distance/ velocity
average velocity
= [total distance traveled]/ [total time elasped]
combination formula
the number of ways that r things can be chosen from n things when order does not matter:
C (n,r) = [n!/(n-r)!•r!]
Permutation formula
the number of ways that r things can be chosen from n things when order does matter:
P (n,r) = [n!/(n-r)!]
binomial probability distribution
the probability that there will be exactly r outcomes out of n trials when the probability of success in each trial is uniformly p:
C (n,r)•pr(1-p)n-r
probability dealing with identical
the number of ways that n things can be ordered when a of them are identical, b of them are identical, c of them are identical, etc. (as in the letters in the word TENNESSEE):
n!/(a!•b!•c!•…)
mean of n scores
µ = Σxi/n
variance
σ2 = Σ(xi - µ)2/n
standard deviation
σ =

Empirical Rule
Logbx = n
bn = x
log(A•B) =
log (A) + log (B)
log(A/B)=
log (A) - log (B)
log(An)=
n•log(A)
x2/a2 + y2/b2 = 1
where a = the semi major axis (the “long radius”)
and b = the semi minor axis (the “short radius”)
c2 = a2 - b2
where c is the distance from the center of the ellipse to either focus.
The total time
Ttotal
The total time Ttotal it takes to complete a task when a task is simultaneously being worked on by more than one agent. If, when working alone, the time it takes one agent to coplete the task is t1, the time it takes another agent is t2, etc., then the total time Ttotal is given by the following formula:
1/t1 + 1/t2 + 1/t3 + etc. = 1/Ttotal
Simple interest
always based on the amoun of the original principal. it thus remains constant for each interest paid (usually measured by the year).
Compound interest
means that new interest is based on an amount equal to the principal plus the total accumulated interest. the amount of interest earned therefore increases each interest period (usually measure by the year).
Rules of exponents
Xn•Xm =
Xn+m
Rules of exponents
1/Xn
= X-n
Rules of exponents
Xn/Xm
Xn-m
or
1/xm-n
Polygon Formulas
N= number of sides of a regular polygon.
S= length from center to a center.
Area = (1/2) N sin(360°/N)S2
Sum of the interior angles = (N-2) x 180°
The number of diagonals = (1/2) N(N-3)
Percent increase and decrease
given 2 numbers X1 and X2, the percent increase or decrease is given by:
D%= (x2-x1)/x1 x 100
If x2 > x1, then D% is positive, representing an increase
If x2 < x1, then D% is negative, representing a decrease
Percentage equations
% = IS/OF x 100
or
% = Part/Whole x 100
Conversions
Temperature
Kelvin (K)
K = °C + 273
Conversions
Temperature
Ferenheit (°F)
°F = 9/5(°C) + 32
Conversions
Temperature
Celsius (°C)
°C = 5/9 (°F - 32)
or
°C = K - 273
1/2
50%
1/3
33.3%
1/4
25%
1/5
20%
1/8
12.5%
1/10
10%
1/20
5%
1/25
4%
12= __ 22= __ 32=__
42=__ 52= __ 62=__
72= __ 82=__ 92=__
102=__ 13=__ 23=__
33=__ 43=__ 53=__
34=__
12=_2_ 22=_4_ 32=_9_
42=_16_ 52= _25_ 62=_36_
72= _49_ 82=_64_ 92=_81_
102=_100_ 13=_1_ 23=_8_
33=_27_ 43=_64_ 53=_125_
34=_81_
Terra
Giga
Mega
Kilo
Centi
Milli
Micro
Nano
Pico
Femto
Terra= 1012
Giga= 109
Mega= 106
Kilo= 103
Centi= 10-2
Milli= 10-3
Micro= 10-6
Nano= 10-9
Pico= 10-12
Femto= 10-15
in. to cm
1in = 2.54 cm
yd to ft.
1 yard = 3ft.
mile to ft.
1 mile = 5280 ft.
mile to km
1 mile = 1.6km
kg to pounds
1 kg = 2.2 lbs
pound to ounces
1 lb = 16 oz.
galloon to quarts
1 gal. = 4 qts.
quart to pints to ounces
1 qt. = 2 pints = 32 fl. oz.
pint to cups
1 pt. = 2 cups
Dilutions
M1V1=M2V2
or
C1V1=C2V2
M=mol/L
log(A) + log(B)
log(A) + log(B) = log(AB)
log(A) - log(B)
log(A) - log(B) = log (A/B)
Rules of exponents
(xa)b
(xa)b = xab
Rules of exponents
(ax)(bx)
(ax)(bx) = (ab)x
Rules of exponents
ax/bx
ax/bx = (a/b)x
Logarithms
log(0.01) = log(10-2) = -2
log(0.1) = log(10-1) = -1
log(1) = log(100) = 0
log(10) = log(101) = 1
log(100) = log(102) = 2
Area of rectangle
A = l x w
Area of parallelogram
A = b x h
Area of trapezoid
A = (baseavg)(height) = (base1 + base2/ 2)(height)
Volume of cone
and
Area of cone
V = 1/3πr2h
A = 1/2C x l
Volume of pyramid
V = 1/3 Abase x h