Two identical circles touch at the point P(9,3)

one of the circles has equation x^2 + y^2 - 10x - 4y +12 = 0

find the equation of the other circle

Guest Oct 27, 2018

#1**+3 **

Lets figure out the standard equation for a circle by completing the square

x^2-10x+25 + y^2-4x+4 = -12 +25 + 4

9x-5)^2 + (y-2)^2 = 17 center is h, k = 5,2

We want a straight line frome center through 9,3 to new center (so the circles will be tangent at 9,3)

5,2 to 9, 3 is a change of 4,1 add that to 9, 3 to get 13,4

SO the identical tangent circle is

(x-13)^2 + (y-4)^2 = 17

ElectricPavlov Oct 27, 2018

#1**+3 **

Best Answer

Lets figure out the standard equation for a circle by completing the square

x^2-10x+25 + y^2-4x+4 = -12 +25 + 4

9x-5)^2 + (y-2)^2 = 17 center is h, k = 5,2

We want a straight line frome center through 9,3 to new center (so the circles will be tangent at 9,3)

5,2 to 9, 3 is a change of 4,1 add that to 9, 3 to get 13,4

SO the identical tangent circle is

(x-13)^2 + (y-4)^2 = 17

ElectricPavlov Oct 27, 2018