Power Series

In mathematics, a power series (in one variable) is an infinite series of the form

where an represents the coefficient of the nth term, c is a constant, and x varies around c (for this reason one sometimes speaks of the series as being centered at c). This series usually arises as the Taylor series of some known function; the Taylor series article contains many examples.

In many situations c is equal to zero, for instance when considering a Maclaurin series. In such cases, the power series takes the simpler form

f(x) = \sum_{n=0}^\infty a_n x^n = a_0 + a_1 x + a_2 x^2 + a_3 x^3 + \cdots.

These power series arise primarily in analysis, but also occur in combinatorics (under the name of generating functions) and in electrical engineering (under the name of the Z-transform). The familiar decimal notation for real numbers can also be viewed as an example of a power series, with integer coefficients, but with the argument x fixed at ⅟10. In number theory, the concept of p-adic numbers is also closely related to that of a power series.

Read more about Power Series:  Examples, Radius of Convergence, Analytic Functions, Formal Power Series, Power Series in Several Variables, Order of A Power Series

Famous quotes containing the words power and/or series:

    “Though I than He—may longer live
    He longer must—than I—
    For I have but the power to kill,
    Without—the power to die—”
    —Emily Dickinson (1830–1886)

    “Rosalynn said, “Jimmy, if we could only get Prime Minister Begin and President Sadat up here on this mountain for a few days, I believe they might consider how they could prevent another war between their countries.” That gave me the idea, and a few weeks later, I invited both men to join me for a series of private talks. In September 1978, they both came to Camp David.”
    —Jimmy Carter (James Earl Carter, Jr.)