STEM · Subjects

Mathematics

Formula references and worked examples for the algebra, geometry, trigonometry, and calculus topics that show up most often in coursework and exams.

Algebra Geometry Trigonometry Calculus How to study math

Foundations

Algebra formula sheet

ConceptFormula
Quadratic formulax = (-b ± √(b² - 4ac)) / 2a, for ax² + bx + c = 0
Slope of a linem = (y² - y¹) / (x² - x¹)
Slope-intercept formy = mx + b
Point-slope formy - y¹ = m(x - x¹)
Difference of squaresa² - b² = (a + b)(a - b)
Perfect square trinomial(a ± b)² = a² ± 2ab + b²
Exponent rulesam·an = am+n, (am)n = amn, a0 = 1
Logarithm identitylogb(x) = y means by = x

Worked example: solve 2x² + 3x - 2 = 0. Here a=2, b=3, c=-2. Plug into the quadratic formula: x = (-3 ± √(9 + 16)) / 4 = (-3 ± 5) / 4, giving x = 0.5 or x = -2.

Shapes & Space

Geometry formula sheet

ShapeAreaPerimeter / Circumference
RectangleA = lwP = 2(l + w)
TriangleA = ½bhP = a + b + c
CircleA = πr²C = 2πr
TrapezoidA = ½(b¹ + b²)h-
SolidVolumeSurface Area
Rectangular prismV = lwhSA = 2(lw + lh + wh)
CylinderV = πr²hSA = 2πrh + 2πr²
SphereV = &frac43;πr³SA = 4πr²
ConeV = ⅓πr²h-

Pythagorean theorem: for a right triangle with legs a, b and hypotenuse c, a² + b² = c².

Angles

Trigonometry reference

RatioDefinition (right triangle)
Sinesin(θ) = opposite / hypotenuse
Cosinecos(θ) = adjacent / hypotenuse
Tangenttan(θ) = opposite / adjacent
Pythagorean identitysin²(θ) + cos²(θ) = 1
Law of sinesa/sin(A) = b/sin(B) = c/sin(C)
Law of cosinesc² = a² + b² - 2ab·cos(C)

Memory trick: SOH-CAH-TOA - Sine = Opposite/Hypotenuse, Cosine = Adjacent/Hypotenuse, Tangent = Opposite/Adjacent.

Change & Accumulation

Calculus quick reference

RuleFormula
Power rule (derivative)d/dx[xn] = nxn-1
Product ruled/dx[fg] = f'g + fg'
Quotient ruled/dx[f/g] = (f'g - fg') / g²
Chain ruled/dx[f(g(x))] = f'(g(x))·g'(x)
Power rule (integral)∫xndx = xn+1/(n+1) + C
Derivative of sin/cosd/dx[sin x] = cos x, d/dx[cos x] = -sin x

Strategy

How to study math effectively

Do problems, don't just read them
Watching a worked example feels like understanding, but math is a skill - you only build it by solving problems yourself, including ones you get wrong.
Redo your mistakes from scratch
When you miss a problem, don't just read the correct answer. Close the solution and try the problem again a day later.
Build a formula sheet as you go
Use the Flashcard Builder to turn each new formula into a card the moment you learn it, rather than cramming them all before a test.

Looking for another subject? See all subjects or head back to Tools.