Thread:HMcCoy/@comment-4531415-20150518211336/@comment-24808864-20150519000957

Before calculus:

Sigma notation is useful as a short-hand for representing finite and infinite sums, usually in a chapter on sequences and series. Knowing the formulas for arithmetic and geometric sequences and/or series can help to ease the process. There are many application of huge sums in business and finance (such as the total amount of money generated by an annuity) or physics (the total amount of distance travelled by a bouncing ball).

During calculus:

Sigma notation is a vital component of second semester calculus (Calc BC). First of all, the integral can be defined as the limit of a Riemann Sum which essentially involves adding up the area of several rectangles. Furthermore, Taylor and Maclaurin showed that functions can be viewed as almost-polynomials, and writing these almost-polynomials ( called power series) is manageable with sigma notation.