Question

If the plane $lx + my + nz = p$ touches the sphere $x^{2} + y^{2} + z^{2} = a^{2}$ then}

• A. $p = a$
• B. $p^{2} = a^{2}(l^{2} + m^{2} + n^{2})$
• C. $l^{2} + m^{2} + n^{2} = a^{2}$
• D. $p = a^{2}$

Hint:

Tangency condition: Distance from center = Radius.

Answer 1

The Correct Option is B