Question 1311

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

Question

The plane p{p} passes through the points with coordinates (3,3,8),{\left( - 3, - 3, - 8 \right),} (8,5,5){\left( 8, 5, 5 \right)} (10,4,4).{\left( - 10, - 4, - 4 \right).}
(i)
Find a cartesian equation of p.{p.}
[4]
The line l1{l_1} has equation
x11=y7=z82x - 11 = y - 7 = \frac{z - 8}{2}
and the line l2{l_2} has equation
x55=y152=z26k,\frac{x - 5}{5} = \frac{y - 15}{- 2} = \frac{z - 26}{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