Square number The result of multiplying a whole number by itself. The
number 9 is a square number because 9 = 3 × 3. The square numbers are 1, 4,
9, 16, 25, 36, 49, 64,...
Square root The number which, when multiplied by itself, equals a given
number. For example, 3 is the square root of 9 because 3 × 3 = 9.
Squaring the circle The problem of constructing a square with the same
area as that of a given circle – using only a ruler for drawing straight lines and a
pair of compasses for drawing circles. It cannot be done.
Symmetry The regularity of a shape. If a shape can be rotated so that it fills
its original imprint it is said to have rotational symmetry. A figure has mirror
symmetry if its reflection fits its original imprint.
Theorem A term reserved for an established fact of some consequence.
Transcendental number A number that cannot be the solution of an
algebraic equation, like ax^2 + bx + c = 0 or one where x has an even higher
power. The number π is a transcendental number.
Twin primes Two prime numbers separated by at most one number. For
example, the twins 11 and 13. It is not known whether there is an infinity of
these twins.
Unit fraction Fractions with the top (numerator) equal to 1. The ancient
Egyptians partly based their number system on unit fractions.
Venn diagram A pictorial method (balloon diagram) used in set theory.
x–y axes The idea due to René Descartes of plotting points having an x-
coordinate (horizontal axis) and y-coordinate (vertical axis).
marcin
(Marcin)
#1