



1) x  x variable  Unknown Value to find.  3x = 6, then x = 2 
2) ≡  Equivalence  Identical to  3 ≡ 3 
3) ≈  Approximately Equal  Approximation  sin(0.02) ≈ (0.02) 
4) ∝  Proportional to.  Proportional to.  f(x) ∝ g(x) 
5) ∞  Lemniscate  Infinity Symbol.  
6) ≠  Not equal.  Inequality  5 ≠ 3 
7) ≤  Inequality  Less than or Equal to.  x + 5 ≤8 ⇒ x ≤ 3 
8) ≥  Inequality  Greater than or Equal to.  x  3 ≥ 10 ⇒ x ≥ 13 
9) ( )  parentheses  calculate expression inside first  2 ∗ (3+5) = 16 
10) [ ]  brackets  calculate expression inside first  [(1+2)∗(1+5)] = 18 
11) ⇒  Implies  Used to write a conclusion  2x=8 ⇒ x = 4 
12) ∴  Therefore  Used to write a conclusion  5x=5 ∴ x = 1 
For US students  For Indian students and UK students 


P > Parenthesis { } E > Exponents M > Multiplication (x) D > Division (÷) A > Addition (+) S > Subtraction () 
B > Bracket { } O > Of (x) D > Division (÷) M > Multiplication (x) A > Addition (+) S > Subtraction () 