Math Formula Encyclopedia
Search, understand, and use formulas across arithmetic, algebra, geometry, trigonometry, calculus, statistics, finance, science, engineering, and everyday math.
134 formulas10 subjectsExamples + variables
AllAlgebra 16Arithmetic 8Calculus 15Everyday Math & Conversions 7Finance & Business 9Geometry 28Number Theory & Sequences 8Science & Engineering 16Statistics & Probability 16Trigonometry 11
4 matching formulas
Trigonometry
Cosine Ratio
cos θ = adjacent/hypotenuse
Right-triangle cosine ratio.
Open formula →TrigonometryPythagorean Identity
sin²θ + cos²θ = 1
Fundamental identity connecting sine and cosine.
Open formula →TrigonometryLaw of Cosines
c² = a² + b² − 2ab cos C
Generalizes the Pythagorean theorem to any triangle.
Open formula →TrigonometryDouble-Angle Cosine
cos(2θ)=cos²θ−sin²θ
Common reference identity or relationship used in trigonometry.
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