Question

If the shortest distance between the line

= ( + 2 + 3) + l₁(2 + 3 + 4) and

= (2 + 4 + 5) + l₂(3 + 4+ 5) is x,

then cos^–1 (cos$\sqrt { 6 }$x) is equal to :

• A. $\frac { 1 } { 2 }$
• B. 0
• C. 1
• D. 2

Answer 1

Answer: (C)

1

Answer 2

line of shortest distance will be along

= –+2–

\ x = (+ 2+2). $\frac { ( - \hat { i } + 2 \hat { j } - \hat { k } ) } { \sqrt { 6 } }$ = $\frac { 1 } { \sqrt { 6 } }$

̃ cos^–1 (cos$\sqrt { 6 }$x) = cos^–1(cos1) = 1