Share
CBSE Class 11 Maths Notes Chapter 13: In CBSE Class 11 Maths, Chapter 13 is all about Limits and Derivatives. These are important ideas in calculus, a branch of math used in many fields. In this chapter, students learn about limits, which show how values get closer to each other.
They also study derivatives, which help find rates of change and slopes of curves. By understanding these concepts, students can solve problems in math, science, and engineering. The notes for this chapter explain these ideas clearly, with examples to help students learn and practice. Mastering limits and derivatives in this chapter sets a strong foundation for future math studies and real-world applications.CBSE Class 11 Maths Notes Chapter 13 PDF
Theorem 1 states various properties of limits for two functions π f and π g :
If both limβ‘π₯βππ(π₯) lim x β a β f ( x ) and limβ‘π₯βππ(π₯) lim x β a β g ( x ) exist, then:We know that
Hence,
Let
be a polynomial function
= lim x β a a 0 + lim x β a a 1 x + lim x β a a 2 x 2 + . . . + lim x β a a n x n =limπ₯βππ0+limπ₯βππ1π₯+limπ₯βππ2π₯2+...+limπ₯βππππ₯π
= a 0 + a 1 lim x β a x + a 2 lim x β a x 2 + . . . + a n lim x β a x n =π0+π1limπ₯βππ₯+π2limπ₯βππ₯2+...+ππlimπ₯βππ₯π
= f ( a ) =π(π)
A rational function π f is one where π(π₯)=π(π₯)β(π₯) f ( x ) = h ( x ) g ( x ) β , and π(π₯) g ( x ) and β(π₯) h ( x ) are polynomials such that β(π₯)β 0 h ( x ) ξ = 0 . Then, limβ‘π₯βππ(π₯)=limβ‘π₯βππ(π₯)β(π₯)=limβ‘π₯βππ(π₯)limβ‘π₯βπβ(π₯)=π(π)β(π) lim x β a β f ( x ) = lim x β a β h ( x ) g ( x ) β = l i m x β a β h ( x ) l i m x β a β g ( x ) β = h ( a ) g ( a ) β However, if β(π)=0 h ( a ) = 0 , there are two scenarios:Theorem 2
For any positive integer n π , lim x β a x n β a n x β a = n a n β 1 limπ₯βππ₯πβπππ₯βπ=πππβ1 .
The proof is shown below.
Dividing ( x n β a n ) (π₯πβππ) by ( x β a ) (π₯βπ) ,
lim x β a x n β a n x β a = lim x β a ( x n β 1 + x n β 2 a + x n β 3 a 2 + . . . + x a n β 2 + a n β 1 ) limπ₯βππ₯πβπππ₯βπ=limπ₯βπ(π₯πβ1+π₯πβ2π+π₯πβ3π2+...+π₯ππβ2+ππβ1)
= a n β 1 + a a n β 2 + . . . + a n β 2 ( a ) + a n β 1 =ππβ1+πππβ2+...+ππβ2(π)+ππβ1
= a n β 1 + a n β 1 + . . . + a n β 1 + a n β 1 ( n terms ) =ππβ1+ππβ1+...+ππβ1+ππβ1(πΒ terms)
= n a n β 1 =πππβ1
Theorem 3
Theorem 4
Theorem 6
Theorem 6 states that the derivative of a function π(π₯)=π₯π f ( x ) = x n is ππ₯πβ1 n x n β 1 for any positive integer π n . Proof: By the definition of the derivative function, we have: πβ²(π₯)=limβ‘ββ0(π₯+β)πβπ₯πβ=limβ‘ββ0β(ππ₯πβ1+β¦+βπβ1)β f β² ( x ) = lim h β 0 β h ( x + h ) n β x n β = lim h β 0 β h h ( n x n β 1 + β¦ + h n β 1 ) β =limβ‘ββ0(ππ₯πβ1+β¦+βπβ1)=ππ₯πβ1 = lim h β 0 β ( n x n β 1 + β¦ + h n β 1 ) = n x n β 1 This can also be proved alternatively: πππ₯(π₯π)=πππ₯(π₯β π₯πβ1) d x d β ( x n ) = d x d β ( x β x n β 1 ) =πππ₯(π₯)β (π₯πβ1)+π₯β πππ₯(π₯πβ1) = d x d β ( x ) β ( x n β 1 ) + x β d x d β ( x n β 1 ) (By the product rule) =1β π₯πβ1+π₯β ((πβ1)π₯πβ2) = 1 β x n β 1 + x β (( n β 1 ) x n β 2 ) (By induction hypothesis) =π₯πβ1+(πβ1)π₯πβ1=ππ₯πβ1 = x n β 1 + ( n β 1 ) x n β 1 = n x n β 1Complete Syllabus : The notes cover all the topics in Chapter 13 as per the CBSE syllabus, ensuring that students don't miss any important concepts.
Key Concepts : They provide a concise and clear explanation of key concepts such as limits, continuity, and derivatives, which are fundamental to understanding calculus.
Easy to Understand : The notes break down complex topics into simpler terms, making it easier for students to grasp difficult concepts..
Self-Study : With comprehensive notes, students can study on their own without much dependence on external help, boosting their confidence.
Concept Clarity : Clear understanding of fundamental concepts helps in building a strong foundation for higher studies.