Questions <!-- TuitionGoWhere generation metadata: stage=3-0; model=google/gemma-4-31b-it; model_label=Gemma 4 31B; generated=2026-05-28; Sources: Stage 2-1 real exam-derived templates and Stage 2-2 exam-enriched syllabus. -->
A-Level Maths H2 Quiz - Vectors Matrices
Name: ____________________
Class: ____________________
Date: ____________________
Score: ________ / 65
Duration: 90 Minutes
Total Marks: 65
Instructions: Answer all questions. Show all necessary working. Use of a non-CAS graphing calculator is permitted.
Section A: Basic Properties & Scalar/Vector Products (Questions 1–7)
Given vectors a = 2 i − 3 j + k \mathbf{a} = 2\mathbf{i} - 3\mathbf{j} + \mathbf{k} a = 2 i − 3 j + k and b = i + j − 2 k \mathbf{b} = \mathbf{i} + \mathbf{j} - 2\mathbf{k} b = i + j − 2 k , find the magnitude of 2 a − 3 b 2\mathbf{a} - 3\mathbf{b} 2 a − 3 b .
[3 marks]
Determine the unit vector in the direction of v = 4 i − 3 j \mathbf{v} = 4\mathbf{i} - 3\mathbf{j} v = 4 i − 3 j .
[2 marks]
Points A A A and B B B have position vectors 3 i − j + 2 k 3\mathbf{i} - \mathbf{j} + 2\mathbf{k} 3 i − j + 2 k and 5 i + 2 j − k 5\mathbf{i} + 2\mathbf{j} - \mathbf{k} 5 i + 2 j − k respectively. Find the vector A B ⃗ \vec{AB} A B and its magnitude.
[3 marks]
Find the scalar product of u = ( 1 − 2 4 ) \mathbf{u} = \begin{pmatrix} 1 \\ -2 \\ 4 \end{pmatrix} u = 1 − 2 4 and v = ( 3 0 − 1 ) \mathbf{v} = \begin{pmatrix} 3 \\ 0 \\ -1 \end{pmatrix} v = 3 0 − 1 .
[2 marks]
Calculate the angle between the vectors a = i + j \mathbf{a} = \mathbf{i} + \mathbf{j} a = i + j and b = i − j \mathbf{b} = \mathbf{i} - \mathbf{j} b = i − j .
[3 marks]
Given a × b = 2 i − j + 3 k \mathbf{a} \times \mathbf{b} = 2\mathbf{i} - \mathbf{j} + 3\mathbf{k} a × b = 2 i − j + 3 k , find the area of the parallelogram with adjacent sides a \mathbf{a} a and b \mathbf{b} b .
[3 marks]
Show that the vectors u = i − 2 j + k \mathbf{u} = \mathbf{i} - 2\mathbf{j} + \mathbf{k} u = i − 2 j + k and v = − 2 i + 4 j − 2 k \mathbf{v} = -2\mathbf{i} + 4\mathbf{j} - 2\mathbf{k} v = − 2 i + 4 j − 2 k are collinear.
[2 marks]
Section B: Lines and Planes (Questions 8–14)
Find the vector equation of the line passing through point P ( 1 , 2 , − 1 ) P(1, 2, -1) P ( 1 , 2 , − 1 ) and parallel to the vector 3 i − j + 4 k 3\mathbf{i} - \mathbf{j} + 4\mathbf{k} 3 i − j + 4 k .
[3 marks]
A line L L L has the equation r = ( 2 1 0 ) + λ ( 1 − 1 2 ) \mathbf{r} = \begin{pmatrix} 2 \\ 1 \\ 0 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ -1 \\ 2 \end{pmatrix} r = 2 1 0 + λ 1 − 1 2 . Find the Cartesian equation of L L L .
[3 marks]
Find the vector equation of the plane passing through A ( 1 , 0 , 2 ) A(1, 0, 2) A ( 1 , 0 , 2 ) , B ( 2 , 1 , 0 ) B(2, 1, 0) B ( 2 , 1 , 0 ) , and C ( 0 , 1 , 1 ) C(0, 1, 1) C ( 0 , 1 , 1 ) .
[4 marks]
Find the Cartesian equation of the plane that passes through the point ( 2 , − 1 , 3 ) (2, -1, 3) ( 2 , − 1 , 3 ) and is perpendicular to the vector 4 i + 2 j − k 4\mathbf{i} + 2\mathbf{j} - \mathbf{k} 4 i + 2 j − k .
[3 marks]
Determine if the lines r 1 = ( 1 0 1 ) + λ ( 1 2 1 ) \mathbf{r}_1 = \begin{pmatrix} 1 \\ 0 \\ 1 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ 2 \\ 1 \end{pmatrix} r 1 = 1 0 1 + λ 1 2 1 and r 2 = ( 2 1 0 ) + μ ( 0 1 − 1 ) \mathbf{r}_2 = \begin{pmatrix} 2 \\ 1 \\ 0 \end{pmatrix} + \mu \begin{pmatrix} 0 \\ 1 \\ -1 \end{pmatrix} r 2 = 2 1 0 + μ 0 1 − 1 are coplanar.
[5 marks]
Find the angle between the plane 2 x − y + 2 z = 5 2x - y + 2z = 5 2 x − y + 2 z = 5 and the plane x + 2 y + 2 z = 10 x + 2y + 2z = 10 x + 2 y + 2 z = 10 .
[4 marks]
Find the coordinates of the foot of the perpendicular from the point ( 1 , 1 , 1 ) (1, 1, 1) ( 1 , 1 , 1 ) to the plane x + y + z = 9 x + y + z = 9 x + y + z = 9 .
[5 marks]
Section C: Advanced Applications & Synthesis (Questions 15–20)
Find the shortest distance from the point P ( 3 , 4 , 5 ) P(3, 4, 5) P ( 3 , 4 , 5 ) to the plane 2 x − 2 y + z = 6 2x - 2y + z = 6 2 x − 2 y + z = 6 .
[4 marks]
A line L L L is given by r = ( 1 2 3 ) + λ ( 2 − 1 1 ) \mathbf{r} = \begin{pmatrix} 1 \\ 2 \\ 3 \end{pmatrix} + \lambda \begin{pmatrix} 2 \\ -1 \\ 1 \end{pmatrix} r = 1 2 3 + λ 2 − 1 1 . Find the equation of the plane containing L L L and the point Q ( 4 , 5 , 6 ) Q(4, 5, 6) Q ( 4 , 5 , 6 ) .
[5 marks]
Find the angle between the line r = ( 0 1 2 ) + λ ( 1 1 0 ) \mathbf{r} = \begin{pmatrix} 0 \\ 1 \\ 2 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ 1 \\ 0 \end{pmatrix} r = 0 1 2 + λ 1 1 0 and the plane x − y + z = 4 x - y + z = 4 x − y + z = 4 .
[5 marks]
Two lines are given by r 1 = a + λ d 1 \mathbf{r}_1 = \mathbf{a} + \lambda \mathbf{d}_1 r 1 = a + λ d 1 and r 2 = b + μ d 2 \mathbf{r}_2 = \mathbf{b} + \mu \mathbf{d}_2 r 2 = b + μ d 2 . If d 1 = ( 1 1 1 ) \mathbf{d}_1 = \begin{pmatrix} 1 \\ 1 \\ 1 \end{pmatrix} d 1 = 1 1 1 and d 2 = ( 1 − 1 0 ) \mathbf{d}_2 = \begin{pmatrix} 1 \\ -1 \\ 0 \end{pmatrix} d 2 = 1 − 1 0 , find the vector n \mathbf{n} n that is perpendicular to both lines.
[3 marks]
Given a triangle A B C ABC A B C with vertices A ( 1 , 2 , 1 ) A(1, 2, 1) A ( 1 , 2 , 1 ) , B ( 3 , 0 , 2 ) B(3, 0, 2) B ( 3 , 0 , 2 ) , and C ( 2 , 2 , 4 ) C(2, 2, 4) C ( 2 , 2 , 4 ) , find the vector equation of the line that is the altitude from A A A to the side B C BC B C .
[6 marks]
A plane Π \Pi Π has the equation x + 2 y − z = 4 x + 2y - z = 4 x + 2 y − z = 4 . A line L L L is perpendicular to Π \Pi Π and passes through the origin. Find the point of intersection of L L L and Π \Pi Π .
[5 marks]
Answers <!-- TuitionGoWhere generation metadata: stage=3-0; model=google/gemma-4-31b-it; model_label=Gemma 4 31B; generated=2026-05-28; Sources: Stage 2-1 real exam-derived templates and Stage 2-2 exam-enriched syllabus. -->
A-Level Maths H2 Quiz - Vectors Matrices (Answer Key)
Section A
2 a − 3 b = ( 4 i − 6 j + 2 k ) − ( 3 i + 3 j − 6 k ) = i − 9 j + 8 k 2\mathbf{a} - 3\mathbf{b} = (4\mathbf{i} - 6\mathbf{j} + 2\mathbf{k}) - (3\mathbf{i} + 3\mathbf{j} - 6\mathbf{k}) = \mathbf{i} - 9\mathbf{j} + 8\mathbf{k} 2 a − 3 b = ( 4 i − 6 j + 2 k ) − ( 3 i + 3 j − 6 k ) = i − 9 j + 8 k .
Magnitude = 1 2 + ( − 9 ) 2 + 8 2 = 1 + 81 + 64 = 146 = \sqrt{1^2 + (-9)^2 + 8^2} = \sqrt{1 + 81 + 64} = \sqrt{146} = 1 2 + ( − 9 ) 2 + 8 2 = 1 + 81 + 64 = 146 .
[3 marks]
∣ v ∣ = 4 2 + ( − 3 ) 2 = 5 |\mathbf{v}| = \sqrt{4^2 + (-3)^2} = 5 ∣ v ∣ = 4 2 + ( − 3 ) 2 = 5 . Unit vector = 4 5 i − 3 5 j = \frac{4}{5}\mathbf{i} - \frac{3}{5}\mathbf{j} = 5 4 i − 5 3 j .
[2 marks]
A B ⃗ = ( 5 − 3 ) i + ( 2 − ( − 1 ) ) j + ( − 1 − 2 ) k = 2 i + 3 j − 3 k \vec{AB} = (5-3)\mathbf{i} + (2-(-1))\mathbf{j} + (-1-2)\mathbf{k} = 2\mathbf{i} + 3\mathbf{j} - 3\mathbf{k} A B = ( 5 − 3 ) i + ( 2 − ( − 1 )) j + ( − 1 − 2 ) k = 2 i + 3 j − 3 k .
Magnitude = 2 2 + 3 2 + ( − 3 ) 2 = 4 + 9 + 9 = 22 = \sqrt{2^2 + 3^2 + (-3)^2} = \sqrt{4 + 9 + 9} = \sqrt{22} = 2 2 + 3 2 + ( − 3 ) 2 = 4 + 9 + 9 = 22 .
[3 marks]
u ⋅ v = ( 1 ) ( 3 ) + ( − 2 ) ( 0 ) + ( 4 ) ( − 1 ) = 3 + 0 − 4 = − 1 \mathbf{u} \cdot \mathbf{v} = (1)(3) + (-2)(0) + (4)(-1) = 3 + 0 - 4 = -1 u ⋅ v = ( 1 ) ( 3 ) + ( − 2 ) ( 0 ) + ( 4 ) ( − 1 ) = 3 + 0 − 4 = − 1 .
[2 marks]
cos θ = a ⋅ b ∣ a ∣ ∣ b ∣ = ( 1 ) ( 1 ) + ( 1 ) ( − 1 ) 2 2 = 0 2 = 0 \cos \theta = \frac{\mathbf{a} \cdot \mathbf{b}}{|\mathbf{a}||\mathbf{b}|} = \frac{(1)(1) + (1)(-1)}{\sqrt{2}\sqrt{2}} = \frac{0}{2} = 0 cos θ = ∣ a ∣∣ b ∣ a ⋅ b = 2 2 ( 1 ) ( 1 ) + ( 1 ) ( − 1 ) = 2 0 = 0 . θ = 90 ∘ \theta = 90^\circ θ = 9 0 ∘ or π / 2 \pi/2 π /2 .
[3 marks]
Area = ∣ a × b ∣ = 2 2 + ( − 1 ) 2 + 3 2 = 4 + 1 + 9 = 14 = |\mathbf{a} \times \mathbf{b}| = \sqrt{2^2 + (-1)^2 + 3^2} = \sqrt{4 + 1 + 9} = \sqrt{14} = ∣ a × b ∣ = 2 2 + ( − 1 ) 2 + 3 2 = 4 + 1 + 9 = 14 .
[3 marks]
v = − 2 ( i − 2 j + k ) = − 2 u \mathbf{v} = -2(\mathbf{i} - 2\mathbf{j} + \mathbf{k}) = -2\mathbf{u} v = − 2 ( i − 2 j + k ) = − 2 u . Since v \mathbf{v} v is a scalar multiple of u \mathbf{u} u , they are collinear.
[2 marks]
Section B
r = ( 1 2 − 1 ) + λ ( 3 − 1 4 ) \mathbf{r} = \begin{pmatrix} 1 \\ 2 \\ -1 \end{pmatrix} + \lambda \begin{pmatrix} 3 \\ -1 \\ 4 \end{pmatrix} r = 1 2 − 1 + λ 3 − 1 4 .
[3 marks]
x − 2 1 = y − 1 − 1 = z 2 \frac{x-2}{1} = \frac{y-1}{-1} = \frac{z}{2} 1 x − 2 = − 1 y − 1 = 2 z .
[3 marks]
A B ⃗ = ( 1 1 − 2 ) \vec{AB} = \begin{pmatrix} 1 \\ 1 \\ -2 \end{pmatrix} A B = 1 1 − 2 , A C ⃗ = ( − 1 1 − 1 ) \vec{AC} = \begin{pmatrix} -1 \\ 1 \\ -1 \end{pmatrix} A C = − 1 1 − 1 .
n = A B ⃗ × A C ⃗ = ( 1 3 2 ) \mathbf{n} = \vec{AB} \times \vec{AC} = \begin{pmatrix} 1 \\ 3 \\ 2 \end{pmatrix} n = A B × A C = 1 3 2 .
Eq: r = ( 1 0 2 ) + λ ( 1 1 − 2 ) + μ ( − 1 1 − 1 ) \mathbf{r} = \begin{pmatrix} 1 \\ 0 \\ 2 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ 1 \\ -2 \end{pmatrix} + \mu \begin{pmatrix} -1 \\ 1 \\ -1 \end{pmatrix} r = 1 0 2 + λ 1 1 − 2 + μ − 1 1 − 1 .
[4 marks]
4 ( x − 2 ) + 2 ( y + 1 ) − 1 ( z − 3 ) = 0 ⟹ 4 x − 8 + 2 y + 2 − z + 3 = 0 ⟹ 4 x + 2 y − z = 3 4(x-2) + 2(y+1) - 1(z-3) = 0 \implies 4x - 8 + 2y + 2 - z + 3 = 0 \implies 4x + 2y - z = 3 4 ( x − 2 ) + 2 ( y + 1 ) − 1 ( z − 3 ) = 0 ⟹ 4 x − 8 + 2 y + 2 − z + 3 = 0 ⟹ 4 x + 2 y − z = 3 .
[3 marks]
d 1 × d 2 = ( 1 2 1 ) × ( 0 1 − 1 ) = ( − 3 1 1 ) \mathbf{d}_1 \times \mathbf{d}_2 = \begin{pmatrix} 1 \\ 2 \\ 1 \end{pmatrix} \times \begin{pmatrix} 0 \\ 1 \\ -1 \end{pmatrix} = \begin{pmatrix} -3 \\ 1 \\ 1 \end{pmatrix} d 1 × d 2 = 1 2 1 × 0 1 − 1 = − 3 1 1 .
P 1 P 2 ⃗ = ( 1 1 − 1 ) \vec{P_1P_2} = \begin{pmatrix} 1 \\ 1 \\ -1 \end{pmatrix} P 1 P 2 = 1 1 − 1 .
Scalar triple product: P 1 P 2 ⃗ ⋅ ( d 1 × d 2 ) = ( 1 ) ( − 3 ) + ( 1 ) ( 1 ) + ( − 1 ) ( 1 ) = − 3 + 1 − 1 = − 3 ≠ 0 \vec{P_1P_2} \cdot (\mathbf{d}_1 \times \mathbf{d}_2) = (1)(-3) + (1)(1) + (-1)(1) = -3 + 1 - 1 = -3 \neq 0 P 1 P 2 ⋅ ( d 1 × d 2 ) = ( 1 ) ( − 3 ) + ( 1 ) ( 1 ) + ( − 1 ) ( 1 ) = − 3 + 1 − 1 = − 3 = 0 .
Not coplanar (skew).
[5 marks]
n 1 = ( 2 − 1 2 ) , n 2 = ( 1 2 2 ) \mathbf{n}_1 = \begin{pmatrix} 2 \\ -1 \\ 2 \end{pmatrix}, \mathbf{n}_2 = \begin{pmatrix} 1 \\ 2 \\ 2 \end{pmatrix} n 1 = 2 − 1 2 , n 2 = 1 2 2 .
cos θ = ∣ ( 2 ) ( 1 ) + ( − 1 ) ( 2 ) + ( 2 ) ( 2 ) ∣ 9 9 = ∣ 2 − 2 + 4 ∣ 9 = 4 9 \cos \theta = \frac{|(2)(1) + (-1)(2) + (2)(2)|}{\sqrt{9}\sqrt{9}} = \frac{|2 - 2 + 4|}{9} = \frac{4}{9} cos θ = 9 9 ∣ ( 2 ) ( 1 ) + ( − 1 ) ( 2 ) + ( 2 ) ( 2 ) ∣ = 9 ∣2 − 2 + 4∣ = 9 4 .
θ = cos − 1 ( 4 / 9 ) ≈ 63.6 ∘ \theta = \cos^{-1}(4/9) \approx 63.6^\circ θ = cos − 1 ( 4/9 ) ≈ 63. 6 ∘ .
[4 marks]
Line through ( 1 , 1 , 1 ) (1,1,1) ( 1 , 1 , 1 ) perp to plane: r = ( 1 1 1 ) + λ ( 1 1 1 ) \mathbf{r} = \begin{pmatrix} 1 \\ 1 \\ 1 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ 1 \\ 1 \end{pmatrix} r = 1 1 1 + λ 1 1 1 .
Substitute into plane: ( 1 + λ ) + ( 1 + λ ) + ( 1 + λ ) = 9 ⟹ 3 + 3 λ = 9 ⟹ λ = 2 (1+\lambda) + (1+\lambda) + (1+\lambda) = 9 \implies 3 + 3\lambda = 9 \implies \lambda = 2 ( 1 + λ ) + ( 1 + λ ) + ( 1 + λ ) = 9 ⟹ 3 + 3 λ = 9 ⟹ λ = 2 .
Point: ( 1 + 2 , 1 + 2 , 1 + 2 ) = ( 3 , 3 , 3 ) (1+2, 1+2, 1+2) = (3, 3, 3) ( 1 + 2 , 1 + 2 , 1 + 2 ) = ( 3 , 3 , 3 ) .
[5 marks]
Section C
Distance = ∣ 2 ( 3 ) − 2 ( 4 ) + 1 ( 5 ) − 6 ∣ 2 2 + ( − 2 ) 2 + 1 2 = ∣ 6 − 8 + 5 − 6 ∣ 3 = ∣ − 3 ∣ 3 = 1 = \frac{|2(3) - 2(4) + 1(5) - 6|}{\sqrt{2^2 + (-2)^2 + 1^2}} = \frac{|6 - 8 + 5 - 6|}{3} = \frac{|-3|}{3} = 1 = 2 2 + ( − 2 ) 2 + 1 2 ∣2 ( 3 ) − 2 ( 4 ) + 1 ( 5 ) − 6∣ = 3 ∣6 − 8 + 5 − 6∣ = 3 ∣ − 3∣ = 1 .
[4 marks]
d = ( 2 − 1 1 ) \mathbf{d} = \begin{pmatrix} 2 \\ -1 \\ 1 \end{pmatrix} d = 2 − 1 1 . P Q ⃗ = ( 3 3 3 ) \vec{PQ} = \begin{pmatrix} 3 \\ 3 \\ 3 \end{pmatrix} P Q = 3 3 3 .
n = d × P Q ⃗ = ( − 6 − 3 9 ) \mathbf{n} = \mathbf{d} \times \vec{PQ} = \begin{pmatrix} -6 \\ -3 \\ 9 \end{pmatrix} n = d × P Q = − 6 − 3 9 or ( 2 1 − 3 ) \begin{pmatrix} 2 \\ 1 \\ -3 \end{pmatrix} 2 1 − 3 .
Eq: 2 ( x − 4 ) + 1 ( y − 5 ) − 3 ( z − 6 ) = 0 ⟹ 2 x + y − 3 z = − 5 2(x-4) + 1(y-5) - 3(z-6) = 0 \implies 2x + y - 3z = -5 2 ( x − 4 ) + 1 ( y − 5 ) − 3 ( z − 6 ) = 0 ⟹ 2 x + y − 3 z = − 5 .
[5 marks]
d = ( 1 1 0 ) , n = ( 1 − 1 1 ) \mathbf{d} = \begin{pmatrix} 1 \\ 1 \\ 0 \end{pmatrix}, \mathbf{n} = \begin{pmatrix} 1 \\ -1 \\ 1 \end{pmatrix} d = 1 1 0 , n = 1 − 1 1 .
sin θ = ∣ d ⋅ n ∣ ∣ d ∣ ∣ n ∣ = ∣ 1 − 1 + 0 ∣ 2 3 = 0 \sin \theta = \frac{|\mathbf{d} \cdot \mathbf{n}|}{|\mathbf{d}||\mathbf{n}|} = \frac{|1 - 1 + 0|}{\sqrt{2}\sqrt{3}} = 0 sin θ = ∣ d ∣∣ n ∣ ∣ d ⋅ n ∣ = 2 3 ∣1 − 1 + 0∣ = 0 .
θ = 0 ∘ \theta = 0^\circ θ = 0 ∘ (Line is parallel to plane).
[5 marks]
n = ( 1 1 1 ) × ( 1 − 1 0 ) = ( 1 1 − 2 ) \mathbf{n} = \begin{pmatrix} 1 \\ 1 \\ 1 \end{pmatrix} \times \begin{pmatrix} 1 \\ -1 \\ 0 \end{pmatrix} = \begin{pmatrix} 1 \\ 1 \\ -2 \end{pmatrix} n = 1 1 1 × 1 − 1 0 = 1 1 − 2 .
[3 marks]
B C ⃗ = ( − 1 2 2 ) \vec{BC} = \begin{pmatrix} -1 \\ 2 \\ 2 \end{pmatrix} B C = − 1 2 2 . Line B C BC B C : r = ( 3 0 2 ) + μ ( − 1 2 2 ) \mathbf{r} = \begin{pmatrix} 3 \\ 0 \\ 2 \end{pmatrix} + \mu \begin{pmatrix} -1 \\ 2 \\ 2 \end{pmatrix} r = 3 0 2 + μ − 1 2 2 .
Foot of perpendicular H H H : A H ⃗ ⋅ B C ⃗ = 0 \vec{AH} \cdot \vec{BC} = 0 A H ⋅ B C = 0 .
H = ( 3 − μ , 2 μ , 2 + 2 μ ) H = (3-\mu, 2\mu, 2+2\mu) H = ( 3 − μ , 2 μ , 2 + 2 μ ) . A H ⃗ = ( 2 − μ , 2 μ − 2 , 1 + 2 μ ) \vec{AH} = (2-\mu, 2\mu-2, 1+2\mu) A H = ( 2 − μ , 2 μ − 2 , 1 + 2 μ ) .
( 2 − μ ) ( − 1 ) + ( 2 μ − 2 ) ( 2 ) + ( 1 + 2 μ ) ( 2 ) = 0 ⟹ − 2 + μ + 4 μ − 4 + 2 + 4 μ = 0 ⟹ 9 μ = 4 ⟹ μ = 4 / 9 (2-\mu)(-1) + (2\mu-2)(2) + (1+2\mu)(2) = 0 \implies -2 + \mu + 4\mu - 4 + 2 + 4\mu = 0 \implies 9\mu = 4 \implies \mu = 4/9 ( 2 − μ ) ( − 1 ) + ( 2 μ − 2 ) ( 2 ) + ( 1 + 2 μ ) ( 2 ) = 0 ⟹ − 2 + μ + 4 μ − 4 + 2 + 4 μ = 0 ⟹ 9 μ = 4 ⟹ μ = 4/9 .
H = ( 23 / 9 , 8 / 9 , 26 / 9 ) H = (23/9, 8/9, 26/9) H = ( 23/9 , 8/9 , 26/9 ) .
Line A H AH A H : r = ( 1 2 1 ) + λ ( 14 / 9 − 10 / 9 17 / 9 ) \mathbf{r} = \begin{pmatrix} 1 \\ 2 \\ 1 \end{pmatrix} + \lambda \begin{pmatrix} 14/9 \\ -10/9 \\ 17/9 \end{pmatrix} r = 1 2 1 + λ 14/9 − 10/9 17/9 .
[6 marks]
Line L L L : r = λ ( 1 2 − 1 ) \mathbf{r} = \lambda \begin{pmatrix} 1 \\ 2 \\ -1 \end{pmatrix} r = λ 1 2 − 1 .
Substitute into plane: λ + 2 ( 2 λ ) − ( − λ ) = 4 ⟹ 6 λ = 4 ⟹ λ = 2 / 3 \lambda + 2(2\lambda) - (-\lambda) = 4 \implies 6\lambda = 4 \implies \lambda = 2/3 λ + 2 ( 2 λ ) − ( − λ ) = 4 ⟹ 6 λ = 4 ⟹ λ = 2/3 .
Point: ( 2 / 3 , 4 / 3 , − 2 / 3 ) (2/3, 4/3, -2/3) ( 2/3 , 4/3 , − 2/3 ) .
[5 marks]