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MathsHardMCQ2023 · 15 Apr Shift 1

Q78.Let the foot of perpendicular of the point P(3, –2, –9) on the plane passing through the points (–1, –2, –3), (9, 3, 4), (9, –2, 1) be Q(α, β, γ). Then the distance Q from the origin is (1) √42 (2) √38 (3) √35 (4) √29

What This Question Tests

This question requires multiple steps: finding the equation of a plane from three points, then determining the foot of the perpendicular from a given point to this plane, and finally calculating the distance of this foot from the origin. It's complex and multi-conceptual.

Concepts Tested

Equation of a plane passing through three pointsEquation of a line perpendicular to a planeFoot of perpendicularDistance formula in 3D

Formulas Used

Equation of plane (r - a) . (b - a) x (c - a) = 0

Equation of line x - x1 / a = y - y1 / b = z - z1 / c

Distance = sqrt((x2-x1)^2 + (y2-y1)^2 + (z2-z1)^2)

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