CBSE Class 12th Exam Date:17 Feb' 26 - 17 Feb' 26
Application of Integrals is like your favourite colouring brush that can fill any shape under every curve, no matter how abstract the shape is. It is a fundamental part of calculus that can help us calculate the area of a certain region, even with no straight sides. In exercise 8.1 of the chapter Application of Integrals, we go beyond the basics of integration and learn about how it's used in our real-life situations, like finding the area of a region or calculating the total distance travelled between two specific points. This article about the NCERT Solutions for Exercise 8.1 of Class 12 Maths, Chapter 8 - Application of Integrals, offers detailed and easy-to-understand solutions for the exercise problems, so that students can clear their doubts and understand the logic behind the solutions. For syllabus, notes, exemplar solutions and PDF, refer to this link: NCERT.
This Story also Contains
Question:1 Find the area of the region bounded by the ellipse $\frac{x^2}{16}+\frac{y^2}{9}=1.$
Answer:
The area bounded by the ellipse : $\frac{x^2}{16}+\frac{y^2}{9}=1.$
Area will be 4 times the area of EAB.
Therefore, Area of EAB = $\int_0^4 y\,dx$
$= \int^4_{0}3\sqrt{1-\frac{x^2}{16}} dx$
$= \frac{3}{4}\int^4_{0}\sqrt{16-x^2} dx$
$= \frac{3}{4}\left [ \frac{x}{2}\sqrt{16-x^2}+\frac{16}{2}\sin^{-1}\frac{x}{4} \right ]^4_{0}$
$= \frac{3}{4}\left [ 2\sqrt{16-16} +8\sin^{-1}(1)-0-8\sin^{-1}(0)\right ]$
$= \frac{3}{4}\left [ \frac{8\pi}{2} \right ]$
$= \frac{3}{4}\left [ 4\pi \right ] =3\pi$
Therefore, the area bounded by the ellipse will be $= 4 \times 3\pi = 12\pi$ units.
Question 2: Find the area of the region bounded by the ellipse $\small \frac{x^2}{4}+\frac{y^2}{9}=1$
Answer:
The area bounded by the ellipse : $\small \frac{x^2}{4}+\frac{y^2}{9}=1$
The area will be 4 times the area of EAB.
Therefore, Area of EAB $= \int_0^2 y\ dx$
$= \int^2_{0}3\sqrt{1-\frac{x^2}{4}} dx$
$= \frac{3}{2}\int^2_{0}\sqrt{4-x^2} dx$
$= \frac{3}{2}\left [ \frac{x}{2}\sqrt4-x^2 +\frac{4}{2}\sin^{-1}\frac{x}{2} \right ]^2_{0}$
$= \frac{3}{2}\left [ \frac{2\pi}{2} \right ]$
$= \frac{3\pi}{2}$
Therefore the area bounded by the ellipse will be $= 4\times \frac{3\pi}{2} = 6\pi$ units.
Question 3: Choose the correct answer in the following
$\small (A)\hspace{1mm}\pi$
$\small (B)\hspace{1mm}\frac{\pi}{2}$
$\small (C)\hspace{1mm}\frac{\pi}{3}$
$\small (D)\hspace{1mm}\frac{\pi}{4}$
Answer:
The area bounded by circle C(0,0,4) and the line x=2 is
The required area = area of OAB
$\int_0^2 y\,dx = \int_0^2 \sqrt{4 - x^2}\,dx$
$= \left[ \frac{x}{2} \sqrt{4 - x^2} + \frac{4}{2} \sin^{-1} \frac{x}{2} \right]_0^2$
$= 2 \cdot \frac{\pi}{2}$
$= \pi$
Hence, The correct answer is $\pi$
Question 4: Choose the correct answer in the following.
(A) $\small 2$
(B) $\small \frac{9}{4}$
(C) $\small \frac{9}{3}$
(D) $\small \frac{9}{2}$
Answer:
The area bounded by the curve $y^2=4x$ and y =3
The required area = OAB
$= \int_0^3 x\,dy$
$= \int_0^3 \frac{y^2}{4}\,dy$
$= \frac{1}{4} \left[ \frac{y^3}{3} \right]_0^3$
$= \frac{9}{4}$
Hence, The correct answer is $\small \frac{9}{4}$
Also Read,
The main topic covered in class 12 maths chapter 8 of Application of Integrals, exercise 8.1 is:
Area under a curve: The exercise starts with calculating the area under the curve $y=f(x)$, between two points on the X axis, as $x=a$ and $x=b$. The area can be found using definite integrals as: $A=\int_a^b f(x) d x$.
Also Read,
Below are some useful links for subject-wise NCERT solutions for class 12.
Here are some links to subject-wise solutions for the NCERT exemplar class 12.
Frequently Asked Questions (FAQs)
13 questions are in total in exercise 8.1 Class 12 Maths.
Mainly area under the curve is discussed in this exercise.
This is very important for boards as well as other subjects like Physics also.
No, it is less difficult than Chapter 7 Integrals.
Maily area and at higher level volume etc. are discussed in this.
Total 3 exercises are there including miscellaneous exercise.
On Question asked by student community
Hello,
The date of 12 exam is depends on which board you belongs to . You should check the exact date of your exam by visiting the official website of your respective board.
Hope this information is useful to you.
Hello,
Class 12 biology questions papers 2023-2025 are available on cbseacademic.nic.in , and other educational website. You can download PDFs of questions papers with solution for practice. For state boards, visit the official board site or trusted education portal.
Hope this information is useful to you.
Hello Pruthvi,
Taking a drop year to reappear for the Karnataka Common Entrance Test (KCET) is a well-defined process. As a repeater, you are fully eligible to take the exam again to improve your score and secure a better rank for admissions.
The main procedure involves submitting a new application for the KCET through the official Karnataka Examinations Authority (KEA) website when registrations open for the next academic session. You must pay the required application fee and complete all formalities just like any other candidate. A significant advantage for you is that you do not need to retake your 12th board exams. Your previously secured board marks in the qualifying subjects will be used again. Your new KCET rank will be calculated by combining these existing board marks with your new score from the KCET exam. Therefore, your entire focus during this year should be on preparing thoroughly for the KCET to achieve a higher score.
For more details about the KCET Exam preparation,
CLICK HERE.
I hope this answer helps you. If you have more queries, feel free to share your questions with us, and we will be happy to assist you.
Thank you, and I wish you all the best in your bright future.
Yes, you can switch from Science in Karnataka State Board to Commerce in CBSE for 12th. You will need a Transfer Certificate from your current school and meet the CBSE school’s admission requirements. Since you haven’t studied Commerce subjects like Accountancy, Economics, and Business Studies, you may need to catch up before or during 12th. Not all CBSE schools accept direct admission to 12th from another board, so some may ask you to join Class 11 first. Make sure to check the school’s rules and plan your subject preparation.
Hello
For the 12th CBSE Hindi Medium board exam, important questions usually come from core chapters like “Madhushala”, “Jhansi ki Rani”, and “Bharat ki Khoj”.
Questions often include essay writing, letter writing, and comprehension passages. Grammar topics like Tenses, Voice Change, and Direct-Indirect Speech are frequently asked.
Students should practice poetry questions on themes and meanings. Important questions also cover summary writing and translation from Hindi to English or vice versa.
Previous years’ question papers help identify commonly asked questions.
Focus on writing practice to improve handwriting and presentation. Time management during exams is key to answering all questions effectively.
This ebook serves as a valuable study guide for NEET 2025 exam.
This e-book offers NEET PYQ and serves as an indispensable NEET study material.
As per latest syllabus. Physics formulas, equations, & laws of class 11 & 12th chapters
As per latest syllabus. Chemistry formulas, equations, & laws of class 11 & 12th chapters
As per latest 2024 syllabus. Study 40% syllabus and score upto 100% marks in JEE
As per latest syllabus. Maths formulas, equations, & theorems of class 11 & 12th chapters