Slope Between Two Points
m=x2−x1y2−y1Displacement from Average Velocity
d=2v0+vtFinal Velocity (Uniform Acceleration)
v=v0+atDisplacement (Uniform Acceleration)
d=v0t+21at2Velocity-Displacement Relation (v² = v₀² + 2ad)
v2=v02+2adVertex x-Coordinate of a Parabola
h=−2abDiscriminant of a Quadratic
Δ=b2−4acVertex y-Coordinate of a Parabola
k=c−4ab2Quadratic Formula (Positive Root)
x=2a−b+b2−4acQuadratic Formula (Negative Root)
x=2a−b−b2−4acSum of the Roots of a Quadratic
S=−abProduct of the Roots of a Quadratic
P=acCompleting the Square: the Constant Needed
k=(2b)2Break-Even Quantity
Q=p−vFMagnitude of a 2D Vector
∣v∣=vx2+vy2Direction Angle of a 2D Vector
θ=atan2(vy,vx)x-Component from Magnitude and Angle
vx=∣v∣cosθy-Component from Magnitude and Angle
vy=∣v∣sinθRight-Triangle Tangent Ratio (TOA)
tanθ=aoResultant of Two Vectors at an Angle
R=A2+B2+2ABcosθLaw of Cosines
c2=a2+b2−2abcosCDot Product of Two 2D Vectors (Components)
a⋅b=axbx+aybyDot Product from Magnitudes and Included Angle
a⋅b=∣a∣∣b∣cosθAngle Between Two 2D Vectors (Components)
θ=arccosax2+ay2bx2+by2axbx+aybyCross Product Magnitude
∣a×b∣=∣a∣∣b∣sinθParallelogram Area from Two Vectors
A=∣axby−aybx∣Triangle Area from Two Vectors
A=21∣axby−aybx∣Work from Force and Displacement Components
W=Fxdx+FydyScalar Projection of One Vector onto Another
compba=∣b∣a⋅bClassical Probability
P=nfOdds and Probability
O=1−PPComplement Rule
P(Ac)=1−P(A)Addition Rule (Mutually Exclusive Events)
P(A∪B)=P(A)+P(B)General Addition Rule
P(A∪B)=P(A)+P(B)−P(A∩B)Multiplication Rule (Independent Events)
P(A∩B)=P(A)P(B)Conditional Probability
P(A∣B)=P(B)P(A∩B)General Multiplication Rule
P(A∩B)=P(A)P(B∣A)Factorial
n!=n×(n−1)×⋯×2×1Permutations (nPr)
nPr=(n−r)!n!Combinations (nCr)
nCr=(rn)=r!(n−r)!n!Binomial Probability
P(X=k)=(kn)pk(1−p)n−kBinomial Distribution Mean
μ=npBinomial Distribution Variance
σ2=np(1−p)Probability of At Least One Success
P=1−(1−p)nExpected Value of a Bet
E=pW−(1−p)LGeometric Distribution (First Success)
P(X=k)=(1−p)k−1pZ-Score (Standard Score)
z=σx−μInterquartile Range (IQR)
IQR=Q3−Q1Range (Max minus Min)
R=xmax−xminVariance and Standard Deviation
σ2=σ⋅σOutlier Lower Fence
LF=Q1−1.5IQROutlier Upper Fence
UF=Q3+1.5IQRRegression Slope from Correlation
b=rsxsyRegression Line Intercept
a=yˉ−bxˉPredicted Value from a Regression Line
y^=a+bxCoefficient of Determination (R²)
R2=r2Percent Error
PE=xacc∣xmeas−xacc∣Weighted Mean of Two Groups
xˉ=n1+n2n1xˉ1+n2xˉ2Simple Interest
I=PrtPercent Change
c=xoldxnew−xoldCompound Interest (Periodic)
A=P(1+nr)ntExponential Growth
A=A0(1+r)tPresent Value
PV=(1+r)tFVRule of 72 (Doubling Time)
n≈i0.72Exponential Growth by Doubling Time
N=N0⋅2t/TSolve an Exponential Equation for the Exponent
x=lnbln(y/a)Future Value of an Annuity (Regular Deposits)
FV=Di(1+i)n−1Loan Payment (Amortized Loan or Mortgage)
M=1−(1+i)−nPiTotal Interest Paid Over a Loan
I=Mn−PEffective Annual Rate from a Nominal Rate
EAR=(1+mr)m−1