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
Sanchit Gupta 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

7 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

7 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

7 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,900
  • View Details
Get extra Rs. 3,180 off
USE CODE: CART20
Get extra Rs. 297 off
USE CODE: CART20

Ask Experts

Have any Question? Ask Experts

Post Question

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