RD Sharma Class 11 Solutions Chapter 21 - Some Special Series (Ex 21.1) Exercise 21.1

‘Some Special Series’ is Chapter 21 in RD Sharma for Class 11. In this chapter, students will learn about different types of series that are used in mathematics equations. Special Series can be defined as the sum of all the numbers of the given sequence. The sequences are of two types infinite as well as finite. In the same way as sequences, the series can also be infinite or finite. Finite series can be defined as a type of series having a finite number of terms and on the other hand, Infinite series can be defined as a type of series having an infinite number of terms (number of elements are not finite). 

For example, consider a sequence as 5, 7, 9,11 … Then the series of these terms will be 5 + 7 + 9 +11 …. . There are different kinds of series that are special in some way or the other are called a special series. ‘Some special series’ chapter is one of the most important chapters for Class 11 students. Under this chapter, students will get to know that the special series can be arithmetic or geometric. There are some types of series whose sum can be defined by some particular formulae. While going through Chapter 21, students will understand the concepts and all their solutions from RD Sharma. Some basic concepts related to special series that a student will learn are:

1.  Special Series with concept of Sum of first n natural numbers

The description of this series is given below:

1+ 2 + 3 + 4 + …. + n = n (n + 1) / 2

2. Special Series with concept of Sum of squares of the first n natural numbers

The description of this series is given below:

12 + 22 + 32 +… + n2  = n(n + 1) (2n + 1)/6

3. Special Series with concept of Sum of cubes of the first n natural numbers

The description of this series is given below:

13 + 23 + 33 + … + n3  = (n (n + 1)/2)2

Advantages of Referring RD Sharma for Class 11 Chapter 21 - Some Special Series Solutions

• The concepts of the Chapter ‘Some Special Series’ for Class 11 are well explained in RD Sharma.

•  All the concepts provided in RD Sharma are in a very detailed way and very easy to understand. 

• For those students who want to practise questions and want to learn the concepts in depth, RD Sharma is the best book to refer to. Students will be able to get the solutions for every question of Exercise 21.1 from Chapter 21. Exercise 21.1 mainly consists of the concept of the sum of n terms. 

• Students should try to solve all the questions because the concepts are very important and practicing them much with the help of Vedantu’s RD Sharma solutions will make it easy to understand the concepts really well. 

• RD Sharma has all the Exercise 21.1 questions and also different types of sample questions that will help to make clarity of types of questions that would come for exams. Referring to RD Sharma Solutions will always be a useful way to learn and grasp the concepts for Class 11 students for math Chapter 21 exercise 21.1 for good understanding and to score good marks.

• These solutions can be downloaded easily for free.