When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. List of trigonometric identities - Wikipedia

    en.wikipedia.org/wiki/List_of_trigonometric...

    Ptolemy's theorem states that the sum of the products of the lengths of opposite sides is equal to the product of the lengths of the diagonals. When those side-lengths are expressed in terms of the sin and cos values shown in the figure above, this yields the angle sum trigonometric identity for sine: sin( α + β ) = sin α cos β + cos α sin ...

  3. Collatz conjecture - Wikipedia

    en.wikipedia.org/wiki/Collatz_conjecture

    Then the formula for the map is exactly the same as when the domain is the integers: an 'even' such rational is divided by 2; an 'odd' such rational is multiplied by 3 and then 1 is added. A closely related fact is that the Collatz map extends to the ring of 2-adic integers , which contains the ring of rationals with odd denominators as a subring.

  4. Elementary algebra - Wikipedia

    en.wikipedia.org/wiki/Elementary_algebra

    For any circle, its circumference c, divided by its diameter d, is equal to the constant pi, (approximately 3.14). Main article: Variable (mathematics) Elementary algebra builds on and extends arithmetic [ 26 ] by introducing letters called variables to represent general (non-specified) numbers.

  5. Multiplication sign - Wikipedia

    en.wikipedia.org/wiki/Multiplication_sign

    In algebraic notation, widely used in mathematics, a multiplication symbol is usually omitted wherever it would not cause confusion: "a multiplied by b" can be written as ab or a b. [1] Other symbols can also be used to denote multiplication, often to reduce confusion between the multiplication sign × and the common variable x.

  6. Algebraic expression - Wikipedia

    en.wikipedia.org/wiki/Algebraic_expression

    In mathematics, an algebraic expression is an expression built up from constants (usually, algebraic numbers) variables, and the basic algebraic operations: addition (+), subtraction (-), multiplication (×), division (÷), whole number powers, and roots (fractional powers).

  7. Extraneous and missing solutions - Wikipedia

    en.wikipedia.org/wiki/Extraneous_and_missing...

    This counterintuitive result occurs because in the case where =, multiplying both sides by multiplies both sides by zero, and so necessarily produces a true equation just as in the first example. In general, whenever we multiply both sides of an equation by an expression involving variables, we introduce extraneous solutions wherever that ...

  8. Equation - Wikipedia

    en.wikipedia.org/wiki/Equation

    The first use of an equals sign, equivalent to 14x + 15 = 71 in modern notation. From The Whetstone of Witte by Robert Recorde of Wales (1557). [1]In mathematics, an equation is a mathematical formula that expresses the equality of two expressions, by connecting them with the equals sign =.

  9. FOIL method - Wikipedia

    en.wikipedia.org/wiki/FOIL_method

    In elementary algebra, FOIL is a mnemonic for the standard method of multiplying two binomials [1] —hence the method may be referred to as the FOIL method. The word FOIL is an acronym for the four terms of the product: First ("first" terms of each binomial are multiplied together)