When we are able to represent in a very concise way a long sequence of numbers using summation/addition we refer to it as sigma Notation. Sigma generally refers to Summation.
A sigma notation calculator is used to calculate the total summation of the given numbers.
Its a shorthand notation usually used to represent sums with more than a few values. This shorthand notation uses the sigma (which denotes sum).We add whatever appears after sigma. Sigma notation is a method where we can write long sum in a precise way.
Solution
This is the sum of all the (x
2+4) terms from x = 1 to x= 4. So we take each value of x, work out for (x
2+4) in each case, and add the results. Therefore
Here we put the value of x as per our given expression which ranges from 1 to 4 and thus solve the expression to get the answer.

This variable n is used to number or label each term.
the number of the first term here is 2
the number of the last term here is 4
Here we can see that the maximum digits till which we have to add is 4 since its given on the top of the sigma and n refers to
the number from which we start here 1. Therefore the summation is from (2+3+4) which gives 9 as a result