Question

Найти радиус сферы

x^2+y^2-2y+z^2+6z-6=0

Answer 1

$x^2+y^2-2y+z^2+6z-6=0\\x^2+(y-1)^2-1+(z+3)^2-9-6=0\\x^2+(y-1)^2+(z+3)^2=16\\R^2=16quad Rightarrow quad R=4\\Centr; ; C(, 0,1,-3)$