Maths

• ∈


  Is an element of
• ∉


  Is not an element of
• ⊆


  Is a subset of
• ⊂


  Is a proper subset of
• {x1, x2,…}

  The set with elements x1 & x2
• {x: …}


  The set of x such that…
• n ( A )

  The number of elements in set A
• Ø


  The empty set
• ε


  The universal set
• A '

  The complement of the set A
• ℕ


  The set of natural numbers {1,2,3…}
• ℤ


  The set of integers
• ℤ+


  The set of positive integers
• ℤ0+


  The set of none negative integers (including zero)
• ℝ


  Set of real numbers
• ℚ


  Set of rational numbers. {p/q: p∈ℤ,q∈ℤ+}
• ∪

  Union
• ∩


  Intersection
• (x,y)


  The ordered pair x,y
• [a,b]

  The closed interval. {x∈ℝ: a≤x≤b}
• [a,b)

  The closed interval. {x∈ℝ: a≤x<b}
• (a,b]

  The interval: {x∈ℝ: a<x≤b}
• (a,b)

  The open interval: {x∈ℝ: a<x<b}
• =


  Is equal to
• ≠


  Is not equal to
• ≡


  Is identical or congruent to
• ≈


  I’d approximately equal to
• ∞


  Infinty
• ∝


  Is proportional to
• ∴


  Therefore
• ∵


  Because
• ⇒


  Implies that
• ⇔


  Both values imply each other
• a

  First term of an arithmetic sequence
• L

  Last term of an arithmetic sequence
• d

  Common difference (arithmetic)
• r


  Common ratio (geometric)
• ∑


  Sum of
• ∏


  Product of
• n!


  Factorial of n