Question

Equation

$ax^{2} + by^{2} + cz^{2} + 2fyz + 2gxz + 2hxy + 2ux + 2vy + 2wz + d = 0$

represents a sphere, if

• A. $a = b = c$
• B. $f = g = h = 0$
• C. $v = u = w$
• D. $a = b = c$ and $f = g = h = 0$

Answer 1

Answer: (D)

$a = b = c$ and $f = g = h = 0$

Answer 2

It is obvious.