📐 Algebra to Calculus
Mathematics Complete Cheatsheet
Algebra, geometry, trig, calculus, probability and statistics in one place.
📖 10 sections
⏱ 28 min read
✅ Quizzes included
🌙 Dark mode
01 Algebra Fundamentals
Commutative
a+b=b+a, a×b=b×a
Associative
(a+b)+c=a+(b+c)
Distributive
a(b+c)=ab+ac
BODMAS
Brackets→Orders→Div/Mul→Add/Sub
Exponent rules
aᵐ·aⁿ=aᵐ⁺ⁿ, (aᵐ)ⁿ=aᵐⁿ, a⁻ⁿ=1/aⁿ
Zero product
If ab=0 then a=0 or b=0
MATHLinear equations
ax + b = c  →  x = (c-b)/a

# Simultaneous (elimination)
2x + 3y = 12
4x - 3y = 6
──────────────
6x = 18  →  x=3, y=2
02 Quadratics
MATHQuadratic formula
ax² + bx + c = 0

         -b ± √(b² - 4ac)
x  =  ─────────────────────
              2a

Δ = b²-4ac:
  Δ > 0  →  2 real roots
  Δ = 0  →  1 repeated root
  Δ < 0  →  no real roots
Sum of roots
r₁+r₂ = -b/a
Vieta's formula
Product of roots
r₁×r₂ = c/a
Vieta's formula
Difference of squares
a²-b² = (a+b)(a-b)
Factoring shortcut
Perfect square
(a±b)² = a²±2ab+b²
Expansion
03 Geometry
Rectangle
A=lw, P=2(l+w)
l=length, w=width
Triangle
A=½bh, P=a+b+c
b=base, h=height
Circle
A=πr², C=2πr
r=radius
Cylinder
V=πr²h, SA=2πr(r+h)
r=radius, h=height
Sphere
V=4/3πr³, SA=4πr²
r=radius
Cone
V=1/3πr²h
h=perpendicular height
Cuboid
V=lwh, SA=2(lw+lh+wh)
l,w,h=dimensions
Pythagoras
c²=a²+b²
Right-angled triangles only
04 Trigonometry
MATHTrig ratios
       Opposite         Adjacent        Opposite
sin θ = ─────────   cosθ = ─────────   tanθ = ─────────
       Hypotenuse        Hypotenuse        Adjacent

Key angles:
  θ     0°    30°    45°    60°    90°
  sin   0     ½    √2/2   √3/2    1
  cos   1    √3/2  √2/2    ½      0
  tan   0    1/√3   1      √3     ∞
Pythagorean
sin²θ+cos²θ=1
Most important identity
Sine rule
a/sinA = b/sinB = c/sinC
Non-right triangles
Cosine rule
c²=a²+b²-2ab cosC
Non-right triangles
Double angle
sin2θ=2sinθcosθ
Radians
π rad=180°
rad = degrees×π/180
05 Derivatives
MATHDifferentiation rules
Power rule:    d/dx[xⁿ] = nxⁿ⁻¹
Constant:      d/dx[c] = 0
Product rule:  d/dx[fg] = f'g + fg'
Quotient rule: d/dx[f/g] = (f'g-fg')/g²
Chain rule:    d/dx[f(g(x))] = f'(g(x))·g'(x)

d/dx[eˣ]=eˣ  d/dx[lnx]=1/x
d/dx[sinx]=cosx  d/dx[cosx]=-sinx
d/dx[tanx]=sec²x
💡
Set f'(x)=0 to find critical points (maxima/minima).
06 Integrals
MATHIntegration rules
∫ xⁿ dx = xⁿ⁺¹/(n+1) + C   (n ≠ -1)
∫ 1/x dx = ln|x| + C
∫ eˣ dx = eˣ + C
∫ sinx dx = -cosx + C
∫ cosx dx = sinx + C
∫ sec²x dx = tanx + C

Definite integral:
∫[a→b] f(x) dx = F(b) - F(a)

Integration by parts:
∫ u dv = uv - ∫ v du
💡
Always write +C for indefinite integrals!
07 Probability
MATHProbability
P(A) = favourable / total
0 ≤ P(A) ≤ 1   P(A') = 1 - P(A)

Addition:     P(A∪B) = P(A)+P(B)-P(A∩B)
Multiplication: P(A∩B) = P(A)×P(B)  [independent]
Conditional:  P(A|B) = P(A∩B)/P(B)

Permutation: P(n,r) = n!/(n-r)!
Combination: C(n,r) = n!/[r!(n-r)!]

Binomial: P(X=k) = C(n,k)pᵏ(1-p)ⁿ⁻ᵏ
Mutually exclusive
P(A∩B)=0, so P(A∪B)=P(A)+P(B)
Independent
P(A∩B)=P(A)×P(B)
Normal dist
68% within 1σ, 95% within 2σ, 99.7% within 3σ
08 Statistics
Mean
x̄ = Σxᵢ/n
Average
Median
Middle value when sorted
Better for skewed data
Variance
σ²=Σ(xᵢ-x̄)²/n
Average squared deviation
Std Dev
σ=√variance
Same units as data
IQR
Q3-Q1
Robust to outliers
Z-score
z=(x-μ)/σ
Standard deviations from mean
Correlation
r: -1 to +1. |r|>0.7=strong, 0.4-0.7=moderate
Central Limit Theorem
Sample means → normal distribution as n→∞
Skewness
Right-skewed: mean>median. Left-skewed: mean
09 Linear Algebra
MATHLinear algebra
# Vectors
v=[a,b,c], u=[d,e,f]
v+u=[a+d,b+e,c+f]
v·u=ad+be+cf  (dot product)
|v|=√(a²+b²+c²)

# Matrix 2×2
A=[[a,b],[c,d]]
det(A) = ad-bc
A⁻¹ = (1/det) × [[d,-b],[-c,a]]

# Multiplication: A(m×n)×B(n×p)=C(m×p)
# NOT commutative: AB ≠ BA
💡
Matrix multiplication is NOT commutative: AB ≠ BA
10 Mini Quizzes
❓ Quiz 1
What does discriminant b²-4ac tell you?
Δ=b²-4ac: Δ>0→2 real roots, Δ=0→1 repeated root, Δ<0→no real roots.
❓ Quiz 2
What is d/dx[sinx]?
d/dx[sinx]=cosx. And d/dx[cosx]=-sinx. d/dx[tanx]=sec²x.
❓ Quiz 3
For independent events A,B: P(A and B)=?
Independent: P(A∩B)=P(A)×P(B). Addition rule P(A)+P(B)-P(A∩B) is for P(A OR B).