The square of the distance of the point ( 157, 327, 7 ) from the line x+13 = y+35 = z+57 in the direction of the vector i + 4 j + 7 k is:
- 66
- 54
- 41
- 44
Answer
(1) 66
Solution
Line through P ( 157, 327, 7 ) along i + 4 j + 7 k: any point is
Q ( 157 + t, 327 + 4t, 7 + 7t )
Q lies on the given line:
227 + t3 = 537 + 4t5 = 12 + 7t7
From the first and last: 7 ( 227 + t ) = 3(12 + 7t)
22 + 7t = 36 + 21t t = -1
Check: each ratio = 57
PQ2 = t2(12 + 42 + 72) = 1 66 = 66
Answer: (1)