Question

Find the value of K such that the equation X^2+Y^2+6x-10y+K=0 represents a circle with a radius of 5.

Answer 1

(x^2 +6x) + (y^2 -10y) +K= 0

Complete the squares of your x and y:

(x^2 +6x +a) + (y^2 -10y +b) = 0; K= a+b


(x^2 +6x +(6/2)^2) + (y^2 -10y +(10/2)^2) = 0

K = 3 + 5 = 8

If I remember it correctly :)

Answer 2

Thank you!

Answer 3

I would need to double check that to be sure if I am right..

Answer 4

I was close. K needs to equal (3)^2+(5)^2 = 9+25 = 34. And the radius of 5 would equal (5)^2 = 25. K=34-25 = 11 is the correct answer.

Answer 5

Thank you very much!

Answer 6

Dont thank me yet, I forgot how to subtract :) 34-25 = 9. Lets go with that :)

Answer 7

I hope I can thank you now.
THANK YOU!

Answer 8

Yep, that one works. Youre Welcome :)