Question 1311

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

Question

The plane p{p} passes through the points with coordinates (7,5,4),{\left( 7, - 5, 4 \right),} (3,13,6){\left( - 3, - 13, 6 \right)} (4,11,7).{\left( 4, - 11, 7 \right).}
(i)
Find a cartesian equation of p.{p.}
[4]
The line l1{l_1} has equation
x6=y81=z+5x - 6 = \frac{y - 8}{-1} = z + 5
and the line l2{l_2} has equation
x33=y+76=z+4k,\frac{x - 3}{3} = \frac{y + 7}{6} = \frac{z + 4}{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