Class 11th Math Sequences And Series Formulas CBSE 2023
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Sequences and Series Class 11 Formulas & Notes

Sequences and Series Class 11 Formulae

Chapter 9 Sequences and Series

Chapter 9 is about sequences and series. It is essential that students study the chapter thoroughly before answering the practice questions. Students should focus on understanding the various concepts related to the chapter so that they can understand the correct approach to answering the questions. The Grade 11 Math notes Kit, Chapter 9 introduces a variety of questions and answers that will greatly improve students' readiness.

Students can greatly improve their preparation by downloading and referencing these study materials in PDF format. All of these learning resources are available free of charge and are available through this page.


Points to Remember

We all are aware of the definition of sequence, Series and Progressions.

  • The sequence is a function whose domain is the set N of natural numbers.

  • Real Sequence: A sequence whose range is a subset of R is called a real sequence.

  • Series : If a1, a2, a3, a4, ………, an, ………. is a sequence, then the expression a1 + a2 + a3 + a4 + a5 + …….. + ……… + an + ……… is a series.

  • A series if finite or infinite according to as the number of terms in the corresponding sequence are finite or infinite.

  • Progressions: It is not necessary that the terms of a sequence always follow a certain pattern or they are described by some explicit formula for the nth term. Those sequences whose terms follow certain patterns are called progressions.

Difference Between Sequences and Series

Let us find out how a sequence can be differentiated with series.



Set of elements that follow a pattern

Sum of elements of the sequence

Order of elements is important

Order of elements is not so important

Finite sequence: 1,2,3,4,5

Finite series: 1+2+3+4+5

Infinite sequence: 1,2,3,4,……

Infinite Series: 1+2+3+4+……

Topics and Sub-topics

The topics and sub-topics of NCERT Class 11 Maths Chapter 9 Sequences And Series are as under:








Arithmetic Progression (A.P.)


Arithmetic Mean


Geometric Progression (G.P.)


General Term of a G.P.


Sum to n terms of a G.P.


Geometric Mean (G.M.)


Relationship Between A.M. and G.M.


Sum to n Terms of Special Series


Learn more about the same in Sequences and Series Class 11 Formulas & Notes pdf.

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Sequences and Series Class 11 Math Formulae Part - 1

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