Question 1311

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

Question

The plane p{p} passes through the points with coordinates (2,4,8),{\left( 2, - 4, - 8 \right),} (0,6,10){\left( 0, - 6, - 10 \right)} (1,4,9).{\left( 1, 4, 9 \right).}
(i)
Find a cartesian equation of p.{p.}
[4]
The line l1{l_1} has equation
x+45=y22=z101\frac{x + 4}{5} = \frac{y - 2}{2} = \frac{z - 10}{-1}
and the line l2{l_2} has equation
x+352=y+235=z6k,\frac{x + 35}{2} = \frac{y + 23}{5} = \frac{z - 6}{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