Posted by Yadlay on .
Consider again the sphere of radius 5 centered at (2, 3,−6). Describe the intersection of the sphere with the xzplane. Write an equation (or equations) for this curve.

Geometry 
Reiny,
Isn't the equation
(x2)^2 + (y3)^2 + (z+6)^2 = 25
And on the xz plane, isn't y = 0 ?
so
(x2)^2 + (03)^2 + (z+6)^2 = 25
(x2)^2 + (z+6)^2 = 25 + 9
(x2)^2 + (z+6)^2 = 34
take it from there.