Question 1311

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

Question

The plane p{p} passes through the points with coordinates (9,8,3),{\left( 9, - 8, - 3 \right),} (7,6,2){\left( 7, - 6, - 2 \right)} (0,1,5).{\left( 0, 1, 5 \right).}
(i)
Find a cartesian equation of p.{p.}
[4]
The line l1{l_1} has equation
x21=y+1=z51\frac{x - 2}{-1} = y + 1 = \frac{z - 5}{-1}
and the line l2{l_2} has equation
x11=y85=z2k,\frac{x - 1}{1} = \frac{y - 8}{- 5} = \frac{z - 2}{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