Question 1311

Vectors II: Lines and Planes
2011 Paper 1 Question 11 Variant

Question

The plane p{p} passes through the points with coordinates (2,3,1),{\left( 2, - 3, 1 \right),} (4,1,3){\left( 4, 1, - 3 \right)} (8,1,3).{\left( - 8, 1, - 3 \right).}
(i)
Find a cartesian equation of p.{p.}
[4]
The line l1{l_1} has equation
x+123=y+95=z75\frac{x + 12}{-3} = \frac{y + 9}{5} = \frac{z - 7}{-5}
and the line l2{l_2} has equation
x+96=y191=z+33k,\frac{x + 9}{- 6} = \frac{y - 19}{- 1} = \frac{z + 33}{k},
where k{k} is a constant. It is given that l1{l_1} and l2{l_2} intersect.
(ii)
Find the value of k.{k.}
[4]
(iii)
Show that l1{l_1} lies in p{p} and find the coordinates of the point at which l2{l_2} intersects p.{p.}
[4]
(iv)
Find the acute angle between l2{l_2} and p.{p.}
[3]

Answer