Q.

The distance of the point (7, –2, 11) from the line x–61=y–40=z–83 along the line x–52=y–1–3=z–56 is :          [2024]

1 18  
2 12  
3 21  
4 14  

Ans.

(4)

Let A be the point (7, –2, 11).

Equation of line AB is x–72=y+2–3=z–116=λ

⇒ x=2λ+7, y=–3λ–2 and z=6λ+11

Point B is of the form (2λ+7, –3λ–2, 6λ+11).

Now, point B lies on the line x–61=y–40=z–83

⇒ 2λ+7–61=–3λ–2–40=6λ+11–83

⇒ –3λ–6=0 ⇒ λ=–2

Thus point B is (3, 4, –1).

∴  Required distance = AB=42+(–6)2+122

.=16+36+144=196=14 units.