The floor of the banquet hall in a hotel is made of polished stone. There is a large chandelier attached to the ceiling of the hall. Consider floor of the hotel as a plane having the equation x - y + z = 4 and chandelier is suspended at the point (1, 0, 1) from the wall. On the basis of above information, answer the following questions. |
The equation of the perpendicular from the point (1, 0, 1) to the plane x - y + z = 4 is: |
$\frac{x}{1}=\frac{y-1}{1}=\frac{z-1}{1}$ $\frac{x-1}{1}=\frac{y}{-1}=\frac{1-z}{-1}$ $\frac{x-1}{-1}=\frac{y-1}{1}=\frac{z}{1}$ $\frac{x-1}{1}=\frac{y}{-1}=\frac{1-z}{1}$ |
$\frac{x-1}{1}=\frac{y}{-1}=\frac{1-z}{-1}$ |
The correct answer is Option 2: $\frac{x-1}{1}=\frac{y}{-1}=\frac{1-z}{-1}$ The equation of the plane is: x − y + z = 4 For a plane of the form ax + by + cz + d = 0, the normal vector to the plane is (a, b, c). A line perpendicular to the plane must have the same direction ratios as the normal vector. The symmetric equation of a line passing through a point (x₁, y₁, z₁) with direction ratios (a, b, c) is (x − x₁)/a = (y − y₁)/b = (z − z₁)/c Substituting: (x₁, y₁, z₁) = (1, 0, 1) and (a, b, c) = (1, −1, 1): (x − 1)/1 = (y − 0)/(−1) = (z − 1)/1 This can also be written as: (x − 1)/1 = y/(−1) = (1 − z)/(−1) which matches Option (2).
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