A line with direction ratios 1, -1, 2 intersects the lines x2= y3= z+13 and x+1-1= y-21= z4 at the points P and Q, respectively. If the length of the line segment PQ is , then 225 2 is equal to:
- 1024
- 1014
- 1104
- 1204
Answer
(2) 1014
Solution
P =(2s, 3s, 3s-1) on the first line, Q =(-1-t, 2+t, 4t) on the second.
PQ=(-1-t-2s, 2+t-3s, 4t-3s+1)= (1, -1, 2)
Adding the first two components: 1-5s=0 s= 15
=-1-t- 25=- 75-t
Third component: 4t- 35+1=2 (- 75-t ) 6t=- 165 t=- 815
=- 75+ 815=- 1315
=PQ=| | 1+1+4= 13 615
225 2=169 6=1014
Answer: (2)