Question:

The equation of the plane that passes through the points \( (1, 0, 2), (-1, 1, 2) \) and \( (5, 0, 3) \) is:

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In a multiple-choice format, it is often faster to plug in a single point. For example, point (5, 0, 3) in option (A) gives \( 5 + 0 - 12 + 7 = 0 \), which is true. Checking the other options with the same point will quickly rule them out.
Updated On: May 1, 2026
  • \( x + 2y - 4z + 7 = 0 \)
  • \( x + 2y - 3z + 7 = 0 \)
  • \( x - 2y + 4z + 7 = 0 \)
  • \( 2y - 4z - 7 + x = 0 \)
  • \( x + 2y + 3z + 7 = 0 \)
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The Correct Option is A

Solution and Explanation


Concept: The general equation of a plane passing through three points \( (x_1, y_1, z_1), (x_2, y_2, z_2), \) and \( (x_3, y_3, z_3) \) can be found using the determinant: \[ \begin{vmatrix} x-x_1 & y-y_1 & z-z_1 \\ x_2-x_1 & y_2-y_1 & z_2-z_1 \\ x_3-x_1 & y_3-y_1 & z_3-z_1 \end{vmatrix} = 0 \] Alternatively, you can test the given points in each option to find which one satisfies all three.

Step 1:
Substitute points into the determinant form.
Using \( P_1(1, 0, 2) \): \[ \begin{vmatrix} x-1 & y-0 & z-2 \\ -1-1 & 1-0 & 2-2 \\ 5-1 & 0-0 & 3-2 \end{vmatrix} = 0 \implies \begin{vmatrix} x-1 & y & z-2 \\ -2 & 1 & 0 \\ 4 & 0 & 1 \end{vmatrix} = 0 \]

Step 2:
Expand the determinant to find the equation.
Expanding along the first row: \[ (x-1)(1 - 0) - y(-2 - 0) + (z-2)(0 - 4) = 0 \] \[ (x-1) + 2y - 4(z-2) = 0 \] \[ x - 1 + 2y - 4z + 8 = 0 \] \[ x + 2y - 4z + 7 = 0 \]
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