Frank P. answered 01/16/16
Tutor
New to Wyzant
Math Tutor for the Grand Junction area
Use the distance equation to find the radius.
Origin is (0,0,0) therefore,
d2 = (xf-xi)2 + (yf-yi)2 +(zf-zi)2
d2 = (1-0)2+(10-0)2+(-5-0)2
d2=1+100+25=126
Now use the equation for a sphere
(x-xc)2+(y-yc)2+(z-zc)2=r2
(x-1)2+(y-10)2+(z+5)2=126