Partial sums

Partial sums refer to the addition of a certain sequence of numbers up to a certain point. For example, if we have the sequence 1, 2, 3, 4, 5, the partial sum up to the third number would be 1+2+3=6.

When we talk about partial sums in the context of calculus, it usually refers to the process of adding up infinitely many terms of a sequence or a series, up to a certain point (which is usually a very large number). This process is used to approximate the value of the series, since it is impossible to add up an infinite number of terms.

The nth partial sum of a series can be denoted as Sn, and it is the sum of the first n terms of the series. As we add more terms to the sum, the value of the partial sum increases, and we can use this knowledge to approximate the value of the series.

Partial sums are particularly useful in numerical integration, where we divide a continuous function into a discrete set of intervals, and then use the sum of the function values in each interval to approximate the integral of the function. This process involves the computation of partial sums, and is the basis for many numerical integration techniques.