The distance of a point from the x-axis is twice its distance from the point (1,2,-1). Find the locus of the point.

Explanation

To find the locus of the point \( P(x, y, z) \) such that the distance from the x-axis is twice its distance from the point \( Q(1, 2, -1) \), we can follow these steps:

### Step 1: Calculate the distance from the point \( P \) to the x-axis.
The distance from a point \( P(x, y, z) \) to the x-axis is given by the formula:
\[ d_{x-axis} = \sqrt{y^2 + z^2} \]

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