Sigma Notation:Definition, Properties and Application

Sigma Notation:Definition, Properties and Application

It provides a concise way to express repetitive calculations and is widely used in various branches of mathematics, statistics, physics, and computer science. This article aims to provide a detailed explanation of summation notation, its components, and its applications.

Summation notation, often represented by the Greek letter sigma (), is a concise mathematical notation used to represent the sum of a series of terms. It provides a shorthand way of expressing repetitive calculations or the accumulation of values.

Summation notation is widely used in mathematics, statistics, physics, computer science, and other fields where the sum of multiple terms needs to be expressed compactly. In this article, we’ll discuss the definition of summation notation, components, properties, and application of summation.

Sigma Notation

Sigma notation, denoted by the symbol , is a concise mathematical notation used to represent the sum of a series of terms, specified by an expression and an index variable within a given range or pattern. Below are components of Sigma Notation:

Index Variable

The index is an integer that ranges over a set of values or follows a particular pattern. The choice of the index variable is arbitrary, and any letter can be used as long as it does not conflict with other variables in the equation.

Lower and Upper Bounds:

 The lower and upper bounds of the index variable define the range over which the terms are summed. The lower bound specifies the starting value of the index variable, while the upper bound indicates the final value. The index variable takes on each value between the lower and upper bounds, inclusive.


The expression represents the terms being summed together. It can be a simple arithmetic formula, a sequence of numbers, a function, or any mathematical operation involving the index variable. The expression is evaluated for each value of the index variable within the specified range, and the results are added together.

Properties and Applications of SigmaNotation

Summation notation possesses several useful properties that make it a powerful tool in mathematical

       1.      Linearity:

Summation notation is linear, meaning that it obeys the properties of linearity. This allows for the distribution of constants, addition or subtraction of individual terms, and factoring out common factors from the expression being summed.

       2.      Distributivity:

Summation notation follows the distributive property, enabling the distribution of the summation over addition or subtraction. This property is particularly useful when dealing with sums of multiple terms or when manipulating complex expressions.

       3.      Manipulation of Index Variable:

 The index variable in summation notation can be modified or transformed, such as changing the starting or ending value, adjusting the step size, or re-indexing to a different set of values. These manipulations allow for simplification or rearrangement of the summation.

Applications Sigma Notation

       1.      Series and Sequences:

Summation notation is frequently used to represent and manipulate series and sequences. It allows for concise representation of arithmetic, geometric, and other types of series, making it easier to compute their sums or analyze their properties.

       2.      Calculus:

In calculus, summation notation is used to express Riemann sums, which are approximations of definite integrals. The notation helps in partitioning an interval and summing the areas of the corresponding rectangles or trapezoids, providing a foundation for integration techniques.

       3.      Statistics:

Summation notation is extensively used in statistics to calculate sample means, variances, and other statistical measures. It simplifies the calculation of sums of squared deviations, cross-products, and other statistical formulas involving the summation of terms.

       4.      Algorithms and Programming:

Summation notation plays a crucial role in algorithm design and programming. It is used to represent iterative processes, such as loops or recursive functions, where the accumulation or summation of values is required. Summation notation helps in formulating efficient algorithms and expressing them concisely in code.

       5.      Physics and Engineering:

 Summation notation finds applications in physics and engineering, where it is used to represent the summation of forces, electric charges, energy, and other physical quantities. It allows for concise representation of complex equations and simplifies calculations in these disciplines.


Example 1:

Find the sum of the first 8 prime numbers



The first eight prime numbers in the series are as follows: f(x)=2, 3, 5, 7, 9, 11, 13, 17, 19.

Step 1:

Write the given prime numbers along with the addition sign between them.

2 + 3 + 5 + 7 + 11 + 13 + 17 + 19

Step 2:

Now calculate the total of the prime number series.

2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 = 77

Example 2:


Solve the series summation


We can find the solution to the given series with a step-by-step solution

We put the value of x=1, 2, 3, 4, 5 in the given series

Step 1:


put the value of x=1

(1)2+7(1) +1=9

Step 2:

For x=2

(2)2+7(2) +1=19

Step 3:

For x=3

(3)2+7(3) +1=31

Step 4:

For x=4

(4)2+7(4) +1=45

Step 5:

For x=5

(5)2+7(5) +1=61

Step 6:

Now put the value of step 1, step 2, step 3, step 4, step 5 in Equation (1)

5x=1(x2+7(x)+1) =9+19+31+45+61= 161

You can use a sigma notation calculatorto find the sum of the function enclosed in sigma from lower to upper limit values with steps.

Question 1:

 What is summation notation?


 Summation notation, also known as sigma notation, is a mathematical notation used to represent the sum of a series of terms. It allows you to compactly express a sum without explicitly writing out each term.

Question 2:

 What does the sigma (∑) symbol represent in summation notation?


 The sigma symbol (∑) represents the sum of a series. It is followed by an expression that specifies the terms to be summed, and the index or variable used to iterate through those terms.

Question 3:

 How do you represent the expression being summed in summation notation?


 The expression being summed is typically written after the sigma symbol (∑). You can use the index or variable of summation in the expression to represent the terms that change as the index iterates.


In this article, we have discussed the definition of summation notation, components, properties, and application of summation. Also, with the help of examples,the topic will be further explained. After completely understanding this article, anyone can defend this topic easily.

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