OCR MEI C4 2011 January — Question 4 7 marks

Exam BoardOCR MEI
ModuleC4 (Core Mathematics 4)
Year2011
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors 3D & Lines
TypeArea of triangle from given side vectors or coordinates
DifficultyModerate -0.3 This is a straightforward application of standard vector techniques: computing dot product to verify perpendicularity (which simplifies part ii), then using the right-angle to find area via ½|AB||BC|. The calculations are routine with no conceptual challenges, making it slightly easier than average, though the multi-step nature and 3D coordinates prevent it from being trivial.
Spec1.10c Magnitude and direction: of vectors1.10d Vector operations: addition and scalar multiplication4.04g Vector product: a x b perpendicular vector

4 The points A , B and C have coordinates \(( 2,0 , - 1 ) , ( 4,3 , - 6 )\) and \(( 9,3 , - 4 )\) respectively.
  1. Show that AB is perpendicular to BC .
  2. Find the area of triangle ABC .

I'd be happy to help clean up mark scheme content, but it appears that only the question number and a simple grid structure were provided in your message:
```
Question 4:
AnswerMarks Guidance
43 2
```
Please provide the actual mark scheme content that needs cleaning up. Once you share the full mark scheme text with:
- Unicode symbols (θ, Σ, ≥, etc.)
- Marking annotations (M1, A1, B1, DM1, etc.)
- Guidance notes
- Any other content
I'll convert it to the format you've requested with LaTeX notation and clear formatting.
I'd be happy to help clean up mark scheme content, but it appears that only the question number and a simple grid structure were provided in your message:

```
Question 4:
4 | 3 | 2 | 1
```

Please provide the actual mark scheme content that needs cleaning up. Once you share the full mark scheme text with:
- Unicode symbols (θ, Σ, ≥, etc.)
- Marking annotations (M1, A1, B1, DM1, etc.)
- Guidance notes
- Any other content

I'll convert it to the format you've requested with LaTeX notation and clear formatting.
4 The points A , B and C have coordinates $( 2,0 , - 1 ) , ( 4,3 , - 6 )$ and $( 9,3 , - 4 )$ respectively.\\
(i) Show that AB is perpendicular to BC .\\
(ii) Find the area of triangle ABC .

\hfill \mbox{\textit{OCR MEI C4 2011 Q4 [7]}}