If the shortest distance between the lines x - 2 = y - 43 = z - 34 and x - 24 = y - 46 = z - 78 is 13 29, then a value of is :
- 1325
- 1
- -1
- - 1325
Answer
(2) 1
Solution
(4, 6, 8) = 2(2, 3, 4) the lines are parallel, b = 2 i + 3 j + 4 k
Points: A( , 4, 3), B(2, 4, 7) AB = (2 - ) i + 4 k
for parallel lines, d = | b AB|| b|
b AB = vmatrix i & j & k \ 2 & 3 & 4 \ 2 - & 0 & 4 vmatrix = 12 i - 4 j + (3 - 6) k
144 + 16 2 + (3 - 6)2 29 = 13 29
25 2 - 36 + 11 = 0
( - 1)(25 - 11) = 0 = 1 or 1125
Answer: (2)