Question:medium

The radius of the sphere $x^{2} + y^{2} + z^{2} + 2x - 4y + 6z + 1 = 0$ is}

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Radius is $\sqrt{u^2+v^2+w^2-d}$. Always halve the coefficients of $x, y, z$ to find $u, v, w$.

Updated On: Jul 3, 2026

$\sqrt{13}$
3
4
$\sqrt{21}$

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The Correct Option is B

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