Find an equation of the sphere with center (-6, -3, 4) and radius 9.

Question

Find an equation of the sphere with center (-6, -3, 4) and radius 9.

Answer 1

The general equation of a sphere is 

(x-x_c)² + (y-y_c)² + (z-z_c)² = r²

where the subscript c refers to the center point of the sphere.

 

(x+6)² + (y+3)² + (z-4)² = 9² = 81

(x+6)² + (y+3)² + (z-4)² = 81

Answer 2

Use the equation (x-h)²+(y-k)²+(z-t)²=r²

 

(x+6)²+(y+3)²+(z-4)²=9²

 

(x+6)²+(y+3)²+(z-4)²=81