Symbol Meaning Symbol Meaning ℕ Set of Natural numbers 훼 − Α Alpha ℤ Set of Integers numbers 훽 − Β Beta ℚ Set of Rational numbers 훾 − Γ Gamma ℝ Set of Real numbers 훿 − Δ Delta ℂ Set of Complex numbers 휀 − Ε Epsilon ∪ The union of 휁 − Ζ Zeta ∩ Intersected with 휂 − Η Eta ⊂ Is a subset of 휃 − Θ Theta ⊆ Is a subset of or equal to 휄 − Ι Iota ⊄ Is not a subset of 휅 − Κ Kappa ⊃ Is a superset of 휆 − Λ Lambda ⊇ Is a superset of or equal to 휇 − Μ Mu ⊅ Is not a superset of 휈 − Ν Nu ∖ Set Difference 휉 − Ξ Xi ∈ Is an element of 휊 − Ο Omicron ∉ Is not an element of 휋 − Π Pi [퐚, 퐛] Closed interval 휌 − Ρ Rho ]퐚, 퐛[ Open interval 휎 − Σ Sigma {퐚, 퐛, 퐜} Set of Elements 휏 − Τ Tau ∅ or { } Empty Set 휐 − Υ Upsilon ( ) Group (do first) 휑 − Φ Phi + Addition (plus, add) 휒 − Χ Chi − Subtraction (minus, subtract) 휓 − Ψ Psi ÷ Division 휔 − Ω Omega × Multiplication (times) ∠ Angle ± Plus-minus ∡ Angle Measure < Is less than ° Degrees ≤ Is less than or equal to ’ Minutes > Is greater than ’’ Seconds ≥ Is greater than or equal to ⊥ Is perpendicular to ⟺ Equivalence ∥ Is parallel to ⟹ Implication (implies) sin() Sine = Equality (is equal to) cos() Cosine ≠ Inequality (is not equal to) tan() Tangent ≅ Approximately (equal to) cot() Cotangent ≡ Congruence 푣⃗ Vector ∑ Summation ‖푣⃗‖ Norm of ∏ Product |푥| Absolute value (modulus) 훁 Gradient 푥̅ Mean ∧ And (propositional logic) 푥̃ Median ∨ Or (propositional logic) log푎() Logarithm with base a ∃ Existential quantification (there is) ln() Natural Logarithm (with base e) ∄ There is not log() Common Logarithm (with base 10) ∀ Universal quantification (for all) 푓(푥) Function ~ or ¬ Negation 푓′(푥) Derivative of Function # Cardinality ∫ Integral (differential calculus) : Such that Dom (f) Domain of the function f ∴ Therefore Ran (f) Range of the function f ∵ Because 푓−1 Inverse Function QED End of proof (quod erat demonstrandum) 푓 ∘ 푔 Function Composition GCD Greatest Common Divisor lim () Limit LCM Lowest Common Multiple 푥 → 푎 x approaches a √ Square Root ∞ Infinity ∛ Cube Root 휋 Pi, 휋 = 3,14159265359 … ! Factorial 푒 Euler's constant, 푒 = 2,7182 … % Percent Φ Golden Ratio, Φ = 1,6180 … ‰ Per mille 푖 Imaginary number, 푖2 = −1 ℉ Degrees Fahrenheit 푅(z) The real part of a complex number ℃ Degrees Celsius 퐼(z) The imaginary part of a complex .