UrbanPro
Login Ask & Answer Success Stories Paid Courses Free Classes Tuition & Classes Fees Write a Review All Categories Help Center
Post your Learning Need Signup as a Tutor
✕

Popular Cities

Bangalore

Hyderabad

Delhi

Mumbai

Chennai

Pune

Kolkata

Gurgaon

Ahmedabad

Jaipur

Noida

✕

Take IIT JEE Coaching from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Book a Free Demo

IIT JEE > Learn IIT JEE Coaching > How to find the no of common tangents to the circles...
✕

Search in

How to find the no of common tangents to the circles x^2 + y^2 = 4 , x^2+y^2 -6x-8y =24

Asked by Last Modified  

10 Answers

Learn IIT JEE Coaching

Follow 10
Answer

Please enter your answer

Tutor

R1 =2 R2 =5 R2-R1=3>0 So there is only one tangent is possible
Comments
Dislike Bookmark

experienced-qualified teacher 11+years of experience

Find the distance between centers, (0,0) and (3,4) which is 5 units. Radius of first is 2 and second is 7. As C1C2=R-r, this implies circles are touching internally. So, only one common tangent is possible.
Comments
Dislike Bookmark

Tutor

Find the distance between the centres of the two circles. Then compare it with the sum of the radii of them. You will come to know if they are touching or intersecting. Depending on the case you will be able to find out the number of common tangents.
Comments
Dislike Bookmark

Top rated IIT JEE Maths Tutor (15 years Experience)

Distance between centres = Sum of radii Three tangents. Two direct common tangent and one indirect common tangent. Distance between centres Sum of radii Two tangents. Two direct common tangents. Distance between centres > Sum of radii Four tangents. Two direct common tangent and two indirect...
read more

Distance between centres = Sum of radii  Three tangents. Two direct common tangent and one indirect common tangent.

Distance between centres  Sum of radii  Two tangents. Two direct common tangents. 

Distance between centres > Sum of radii  Four tangents. Two direct common tangent and two indirect common tangents.

read less
Comments
Dislike Bookmark

Teacher, Mathematician, Tutor

Check centers and radii of both circles and hence 1.) if they intersect then two common tangents 2.) If they touch then 3 common tangents 3.) If they do not touch then 4 common tangents
Comments
Dislike Bookmark

Tutor

Centre of first Circle is A(0,0) and second centre is B(3,4). So distance between centres is 5. Radius of first circle=x=2 and radius of second y=7 So AB=|x-y|. So circles touch internally. Hence only one common tangent.
Comments
Dislike Bookmark

Tutor

These 2 cicle touch each other internally. You can find out the touching in the ratio of 2:7 externally (0,0) and (3,4) That point is point of contact. From that point T=0 , for any circle will give equation of tangent
Comments
Dislike Bookmark

Mechanical Engineering Postgraduate from IIT

Let R and r be the radii of the two circles. Find out the distance d between the centres of the circles. Then, If d< abs(R-r), no common tangents If d = abs(R-r), one common tangent If abs(R-r) ≤ d ≤ max(R,r), two common tangents If d = max(R,r), three tangents If d > max(R,r), four...
read more

Let R and r be the radii of the two circles. Find out the distance d between the centres of the circles. Then,

If d< abs(R-r), no common tangents

If d = abs(R-r), one common tangent

If abs(R-r) ≤ d ≤  max(R,r), two common tangents

If d = max(R,r), three tangents

If d > max(R,r), four tangents.

read less
Comments
Dislike Bookmark

JEE Main Maths, Physics With 12 years exp.

Here only one common tangent can be drawn as the first circle is completely inside the second circle and touching internally since distance b/w their centres is equal to difference of their radii.
Comments
Dislike Bookmark

Quicker Maths

First of all calculate the distance between centers of circle C (0,0) and C' (3,4) which is 5 units.By comparing general equation of circle, Radius of first circle is 2 unit and that of second is 7unit. As CC'=R-r, it means circles are touching internally. Hence, we can say that only one common tangent...
read more

First of all calculate the distance between centers of circle C (0,0) and C' (3,4) which is 5 units.By comparing general equation of circle, Radius of first circle is 2 unit and that of second is 7unit. As CC'=R-r, it means circles are touching internally. Hence, we can say that only one common tangent is possible. 

read less
Comments
Dislike Bookmark

View 8 more Answers

Related Questions

Is it very necessary to go for coaching classes for case class 12?
It's not necessarily , if you are thorough with the concept. Moreover you need to find time to solve problems and practice model papers.
D
0 0
5
A concave lens of refractive index 1.5 is immersed in a medium of refractive index 1.65. What is the nature of the lens ?
Since refractive index of lens is less than refractive index of surroundings, it will behave as a convex lens.
Jagadeesh
1 0
9
How to prepare for JEE Main?
Students must give equal weightage to all the subjects, prepare a time table and follow it properly. Remember it is the quality of time spent and not the quantity alone. Hence, take short breaks of 5 to...
Nilay
Its now less than two months for my kids 12th board exam. Do you have any last minute mock exams for my kid for PCM?
I have several mock exams from institutes like FIIT-JEE and Ressonance. But would like to know the preference being board or IIT-JEE?
Salim
0 0
7
Is coaching important for the class 12 science exam?
No need. The thing is you must have basics and be upto date in reading and learning. Just need a compressuve reading of lessons as many times as possible and practice bits questions. It is enough to get good result.
Mrinal Kanti
0 0
5

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Mathematics With Practical Approach.
Mathematics is a subject, it requires not only practice but a deep understanding and fun in learning new things. Math is always can learn in a easy and interesting with PRAGMATIC way. Students must understand...

Ramesh Babu Mallela

0 0
0
Rational Numbers
A number of the form p/q where q not equals to zero is called a rational numbers. P may be zero or may not. P and q are positive /negative integers. It denotes the part of a quantity...
M

Mohit S.

1 0
0
Atomic Structure
All substances are made from atoms. Each atom is made of a nucleus - containing protons and neutrons - surrounded by electrons. The atomic number is the number of protons in an atom. The elements are...

Tejas Academy Centre

1 0
0
Innequalities basics part 4

Rajan Mittal

0 0
0
Derive An Expression For Drift Velocity Of Free Electrons
Derive an expression for drift velocity of free electrons. How does drift velocity of electrons in a metallic conductor vary with increase in temperature ? Explain. (i) When conductor is subjected to...

Sujoy Das

7 1
1

Recommended Articles

How to prepare for JEE Physics paper?

JEE is one of the most prestigious engineering exams in India. It is considered as the gateway to the world of immense possibilities. Competing in JEE exam requires focus and devotion to each of the three subjects - Physics, Chemistry and Mathematics. Coming to Physics, it happens to be one of the most loved subjects which...

Read full article >

Get an Expert’s Guide and Tips to Make it...

An exclusive interview with Dr. Ashok Gopalakrishnan, CEO, Magnificient2 Software Services & Technology Inc. on approaching the JEE exam and how to make it to one of the IITs. Flexiguru.com: Flexiguru.com is an e-learning company offering flexible learning solutions that enhance teaching and learning. Launched with...

Read full article >

IIT Foundation Course: Five Joining Benefits

Do you want to become an Engineer? If your answer is YES, then plan your career right from an early age. To reach your ultimate goal, you need to take right actions at the right time, to increase your chances of success. Make your dream of becoming an IITian true in future, by taking up the right course at the right age....

Read full article >

Why You Should Switch to Online Coaching...

Looking forward to become an IITian? Searching for best coaching mode to prepare for IIT JEE exam? Then look no further than IIT JEE online coaching classes and start preparing for the test anywhere anytime, as per your convenience. With better connectivity provisions in India, now more and more students are connected...

Read full article >

Find IIT JEE Coaching near you
IIT JEE Coaching in Mumbai
IIT JEE Coaching in Delhi
IIT JEE Coaching in Bangalore
IIT JEE Coaching in Kolkata
IIT JEE Coaching in Chennai
IIT JEE Coaching in Hyderabad
IIT JEE Coaching in Pune
IIT JEE Coaching in Jaipur
IIT JEE Coaching in Chandigarh
IIT JEE Coaching in Ahmedabad
Online IIT JEE Coaching

Looking for IIT JEE Coaching ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for IIT JEE Coaching Classes?

The best tutors for IIT JEE Coaching Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Take IIT JEE Coaching with the Best Tutors

The best Tutors for IIT JEE Coaching Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more

ThinkVidya Learning Pvt Ltd © 2010-2024All Rights Reserved