| Exam Board | OCR |
|---|---|
| Module | Further Additional Pure AS (Further Additional Pure AS) |
| Year | 2018 |
| Session | June |
| Marks | 8 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Vector Product and Surfaces |
| Type | Area of triangle using vector product |
| Difficulty | Standard +0.3 This is a straightforward application of the vector product formula for triangle area (½|AB × AC|), followed by using the area-base-height relationship. While it's a Further Maths topic, the question requires only direct application of standard formulas with no conceptual challenges or novel insights, making it slightly easier than average overall. |
| Spec | 4.04g Vector product: a x b perpendicular vector4.04h Shortest distances: between parallel lines and between skew lines |
| Answer | Marks | Guidance |
|---|---|---|
| 1 | (i) | 7 10 3 |
| Answer | Marks |
|---|---|
| Area ABC = 1 | their (b – a) (c – a) |
| Answer | Marks |
|---|---|
| 2 | B1 |
| Answer | Marks |
|---|---|
| A1 | 1.1a |
| Answer | Marks |
|---|---|
| 1.1 | Any two of these |
| Answer | Marks |
|---|---|
| (ii) | AB = 50 or 5 2 |
| Answer | Marks |
|---|---|
| 5 2 50 50 10 | B1 |
| Answer | Marks |
|---|---|
| A1 | 1.1 |
| Answer | Marks |
|---|---|
| 1.1 | FT their (b – a) from (i) |
| Answer | Marks |
|---|---|
| cao any exact surd form | 3.3 2 or 21.78 also ok |
Question 1:
1 | (i) | 7 10 3
b – a = 0, c – a = 4, c – b = 4
1 1 2
4
(b – a) (c – a) = 17
28
Area ABC = 1 | their (b – a) (c – a) |
2
33
=
2 | B1
M1
A1
M1
A1 | 1.1a
1.1a
1.1
1.2
1.1 | Any two of these
Attempt at a suitable vector product
FT correct
FT in surd, rational or decimal form
[5]
(ii) | AB = 50 or 5 2
Area ABC = 1 (AB) d = 33
2 2
33 33 33 50 33 2
d = , , ,
5 2 50 50 10 | B1
M1
A1 | 1.1
1.1a
1.1 | FT their (b – a) from (i)
Equating 1 baseht. (correct
2
setting) to (i)’s answer
cao any exact surd form | 3.3 2 or 21.78 also ok
[3]
1 The points $A , B$ and $C$ have position vectors $6 \mathbf { i } + 2 \mathbf { j } + 4 \mathbf { k } , 13 \mathbf { i } + 2 \mathbf { j } + 5 \mathbf { k }$ and $16 \mathbf { i } + 6 \mathbf { j } + 3 \mathbf { k }$ respectively.\\
(i) Using the vector product, calculate the area of triangle $A B C$.\\
(ii) Hence find, in simplest surd form, the perpendicular distance from $C$ to the line through $A$ and $B$.
\hfill \mbox{\textit{OCR Further Additional Pure AS 2018 Q1 [8]}}