NCERT Solutions for class 11 Maths Chapter 9: Sequences and Series

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NCERT Solutions for Class 11 Maths Chapter 9 Sequences and Series are added in the article. A sequence is a list of elements that can be repeated in any order, whereas a series is the total of all elements. An arithmetic progression is one of the most common examples of sequence and series.

Key concepts covered in NCERT Solutions Class 11 Maths Chapter 9 Sequence and Series are:

Download: NCERT Solutions for Class 11 Mathematics Chapter 9 pdf

Class 11 Maths NCERT Solutions Chapter 9 Sequence and Series

Class 11 Maths NCERT Solutions Chapter 9 Sequence and Series are provided below:

Also check: Sequence and Series

Important Topics for Class 11 Maths NCERT Solutions Chapter 9 Sequence and Series

Important Topics for Class 11 Maths NCERT Solutions Chapter 9 Sequence and Series are elaborated below:

Arithmetic Progression (A.P.)

An Arithmetic Progression (AP) is a sequence where differences between every two consecutive terms are the same. There is a possibility to derive a formula for the n^th term.

Example: Find the general term of the arithmetic progression -3, -(1/2), 2…

Solution: Given sequence is -3, -(1/2),2…

Here, first term is a=-3, and common difference is:

d = -(1/2) -(-3) = -(1/2)+3 = 5/2

By AP formulas, the general term of an AP is calculated by the formula:

an = a+(n-1)d

an = -3 +(n-1) 5/2

= -3+ (5/2)n - 5/2
= 5n/2 - 11/2

Thus, general term of the given AP is: an = 5n/2 - 11/2

Geometric Progression (G. P.)

In a geometric progression, each successive term is obtained by multiplying the common ratio to its preceding term. The formula for the nth term of a geometric progression whose first term is a and common ratio is r is:

a_n=ar_n-1

Geometric Mean (G.M.)

Geometric Mean (GM) is average value or mean which signifies central tendency of the set of numbers by finding product of their values.

Example: What is the geometric mean of 4,8.3,9 and 17?

Solution: Multiply the numbers together and then take the 5th root (because there are 5 numbers) = (4 * 8 * 3 * 9 * 17)(1/5) = 6.81

NCERT Solutions For Class 11 Maths Chapter 9 Exercises:

The detailed solutions for all the NCERT Solutions for Chapter 9 Sequence and Series under different exercises are as follows:

Also check:

Important Chapter Related Links
Harmonic Mean	Sum of Squares	Difference between Sequence and Series
Summation Formula	Geometric Series Formula	Sum of Arithmetic Sequence Formula
Sum Of Cubes Formula	Arithmetic Mean Formula	Arithmetic Sequence Explicit Formula
Arithmetic Sequence Recursive Formula	Difference of Cubes Formula	Difference of Squares Formula
Fourier Series Formula	Infinite Geometric Series Formula	Infinite Series Formula
Taylor Series Formula	Prime Number Formula	Arithmetic Geometric Sequence

Also check:

Math Study Guides
Maths Important Formulas	Maths MCQs	Comparison Articles in Maths
Difference Between Topics in Maths	Math Study Material	Arithmetic

CBSE CLASS XII Related Questions

1.
Assertion (A) : In an experiment of throwing an unbiased die, the probability of getting a prime number given that number appearing on the die being odd is \( \frac{2}{3} \).
Reason (R) : For any two events \( A \) and \( B \), \( P(A|B) = \frac{P(A \cup B)}{P(B)} \).
- Both Assertion (A) and Reason (R) are true and the Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true and Reason (R) is false.
- Assertion (A) is false and Reason (R) is true.
View Solution
2.
For two vectors \(\vec{a}\) and \(\vec{b}\):

Assertion (A): \[ |\vec{a}\times\vec{b}|^2+(\vec{a}\cdot\vec{b})^2 = |\vec{a}|^2|\vec{b}|^2 \] Reason (R): \[ |\vec{a}\times\vec{b}| = (\vec{a}\cdot\vec{b})\tan\theta, \quad \theta\neq\frac{\pi}{2}. \]
- Both Assertion (A) and Reason (R) are true and the Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
View Solution
3.
Find: \[ \int \frac{x^2}{(x^2+9)(x^2+16)}\,dx \]
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4.
The domain of \[ f(x)=\cos^{-1}(2x-5) \] is:
- \([-1, 1]\)
- \([4, 6]\)
- \([-7, -3]\)
- \([2, 3]\)
View Solution
5.
Evaluate: \[ \cos\left[\sin^{-1}(-1)-\tan^{-1}(-\sqrt{3})\right]. \]
View Solution
6.
For a square matrix \(A\), \[ (3A)^{-1}= \]
- \( 3A^{-1} \)
- \( 9A^{-1} \)
- \( \frac{1}{3} A^{-1} \)
- \( \frac{1}{9} A^{-1} \)
View Solution