Question

The radius of the sphere x² + y² + z² + 6x - 2y + 4z + 5 = 0 is,​

Answer 1

Answer:

Radius of the sphere is r=

1

2

+(−1)

2

+(−2)

2

+19

=5

And center of the sphere is C=(−1,1,2)

Now distance of the given plane from the centre is CP=

1+4+4

−1+2+4+7

=4

Hence radius of the circle is =

r

2

−CP

2

=3