MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12
        

The number of circles having radius 5 and passing through the points (-1, 0) and (4,0) is


(a) 1 (b) 2 (c) 4 (d) infinite

10 years ago

Answers : (2)

Badiuddin askIITians.ismu Expert
147 Points
							

Dear sanchit

let center of circle is (h,k)

so (h+1)2 +(k)2 =25 .......1

and (h-4)2 +(h)2 =25 .........2

 

from equation 1 and 2

   (h+1)2=(h-4)2

h=3/2

put this value in equation 1

k=±5 √3/2

so two circle is possible

Please feel free to post as many doubts on our discussion forum as you can. If you find any question Difficult to understand - post it here and we will get you the answer and detailed solution very quickly.
 We are all IITians and here to help you in your IIT JEE preparation.

 All the best.
 
Regards,
Askiitians Experts
Badiuddin

10 years ago
Askiitians Expert Bharath-IITD
23 Points
							

Dear Sanchit,

Let the circle centre be (a,b)

Now equation of that circle with radius 5 is given by

( x - a )2 + ( y - b )2 = 25......................Eq(1)

Given that this circle passes through (-1,0) and (4,0)

Then by substituting these points in the equation(1) we get

(- a - 1 )2 + b2 = 25........Eq(2) 

and 

( 4 - a )2 + b2 = 25.........Eq(3)

Substracting Eq(2) and Eq(3) gives us the value of a = 1.5

 

Now Substitute this 'a' value in either Eq(1) or Eq(2) to give two b vaues they are +2.5√3 and -2.5√3

Thus two circles are possible with centers ( 1.5 , 2.5√3 ) and ( 1.5 , -2.5√3 )

So, the answer is (b)


Please feel free to post as many doubts on our discussion forum as you can. If you find any question
Difficult to understand - post it here and we will get you the answer and detailed solution very quickly. We
are all IITians and here to help you in your IIT JEE preparation.


All the best !!!

 


Regards,

Askiitians Experts

Adapa Bharath

10 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 731 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 53 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details