Question:

The radius of the sphere $x^2 + y^2 + z^2 = 12x + 4y + 3z$ is

Show Hint

For sphere $x^2+y^2+z^2+2ux+2vy+2wz+d=0$, radius is $\sqrt{u^2+v^2+w^2-d}$.
Updated On: Apr 10, 2026
  • $\frac{13}{2}$
  • 13
  • 26
  • 52
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Step 1: Standard Form
Rewrite the equation as $x^2 + y^2 + z^2 - 12x - 4y - 3z = 0$. Here $u = -6, v = -2, w = -3/2$ and $d = 0$.
Step 2: Calculate Radius

Radius $R = \sqrt{u^2 + v^2 + w^2 - d}$. $R = \sqrt{(-6)^2 + (-2)^2 + (-3/2)^2 - 0}$. $R = \sqrt{36 + 4 + 9/4} = \sqrt{40 + 9/4} = \sqrt{169/4}$.
Step 3: Conclusion

$R = 13/2$.
Final Answer: (a)
Was this answer helpful?
0
0