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Home > Three Dimensional Geometry
Find the point on the line x + 23 = y + 12 = z - 32 at a distance 3 2 from the point(1, 2, 3).
Let x + 23 = y + 12 = z - 32 = λx = -2 + 3λ, y = -1 + 2λ, z = 3 + 2λTherefore, a point on this line is: { ( -2 + 3λ ), (-1 + 2λ ), ( 3 + 2λ ) }The distance of the point { ( -2 + 3λ ), (-1 + 2λ ), ( 3 + 2λ ) } from point ( 1, 2, 3 ) = 32∴ -2 + 3λ - 12 + -1 + 2λ - 22 + 3 + 2λ - 32 = 32⇒ -3+ 3λ 2 + -3 + 2λ 2 + 2λ 2 = 18⇒ 9+ 9λ 2 - 18λ + 9 + 4λ 2 - 12λ + 4λ 2 = 1817λ 2 - 30λ = 0λ = 0, λ = 3017When λ = 3017,
x = -2 + 3λ = -2 + 3 3017 = -2 + 9017 = 5617y = -1 + 2λ = 1 + 2 3017 = 1 + 6017 = 4317z = 3 + 2λ = 3 + 2 3017 = 51 + 6017 = 11117thus, when λ = 3017, the point is 5617, 4317, 11117 and when λ = 0, the point is ( -2, -1, 3 ).
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