Skip to content
G24

Describe translations as 2D vectors

Vectors as translations

Worked answers, methods and verified real exam appearances for G24 on Edexcel GCSE Maths 1MA1.

Explanation

  • A translation moves every point by the same horizontal and vertical displacement, preserving lengths, angles and orientation. Describe it with a column vector (xy)\binom{x}{y}: a positive top component moves right and a negative one moves left; a positive bottom component moves up and a negative one moves down.
  • To recover the vector from object and image coordinates, calculate image minus object in each coordinate.
  • Apply the same vector to every vertex when constructing an image.
  • Examiners expect a vector, not a destination coordinate, and the object-to-image direction matters.
  • Matching one pair of corresponding points is enough if the shapes are genuinely translations.
A translation gives every corresponding point the same displacement vector.

Worked example

Point A(2,5)A(-2,5) is translated to A(4,1)A'(4,1). Find the translation vector.

  1. 1.Horizontal displacement =4(2)=6=4-(-2)=6.
  2. 2.Vertical displacement =15=4=1-5=-4.
  3. 3.Write horizontal above vertical in a column vector.

Answer: (64)\binom{6}{-4}.

Common mistakes

  • Don't subtract object minus image and obtain the reverse vector.
  • Don't write (4,1)(4,1), the image coordinate, instead of the displacement vector.

Exam tip

Use image minus object for both coordinates, then check the signs against the visible direction of movement.

Worked practice

Q1
Tier 1 · Easy

1

Point A=(3,4)A=(-3,4) is translated to A=(2,1)A'=(2,-1). Describe the translation as a vector.

(2)

(Total for Question 1 is 2 marks)

Mark scheme

Mark scheme for question 1
QuestionAnswerMarkMark scheme
1
  • (55)\binom{5}{-5}
2Calculate image minus object in each coordinate: 2(3)=52-(-3)=5 and 14=5-1-4=-5. The translation vector is (55)\binom{5}{-5}.
Q2
Tier 2 · Standard

2

Triangle ABCABC has vertices A=(1,2)A=(1,-2), B=(5,1)B=(5,1) and C=(2,4)C=(2,4). It is translated by (43)\binom{-4}{3}. Write the coordinates of the three image vertices.

(3)

(Total for Question 2 is 3 marks)

Mark scheme

Mark scheme for question 2
QuestionAnswerMarkMark scheme
2
  • A=(3,1)A'=(-3,1)
  • B=(1,4)B'=(1,4)
  • C=(2,7)C'=(-2,7)
3Add 4-4 to every xx-coordinate and 33 to every yy-coordinate. This gives A=(3,1)A'=(-3,1), B=(1,4)B'=(1,4) and C=(2,7)C'=(-2,7).
Q3
Tier 3 · Hard

3

A translation maps P=(6,4)P=(-6,4) to P=(1,2)P'=(1,-2). The same translation maps Q=(3,k)Q=(3,k) to Q=(10,5)Q'=(10,5). Find kk and describe the translation as a vector.

(4)

(Total for Question 3 is 4 marks)

Mark scheme

Mark scheme for question 3
QuestionAnswerMarkMark scheme
3
  • k=11k=11
  • (76)\binom{7}{-6}
4From PP to PP', the displacement is 1(6)=71-(-6)=7 horizontally and 24=6-2-4=-6 vertically, so the vector is (76)\binom{7}{-6}. Therefore the image of Q=(3,k)Q=(3,k) has yy-coordinate k6k-6. Since k6=5k-6=5, k=11k=11.
Q4
Tier 1 · Easy

4

Point P=(4,1)P=(4,-1) is translated by (35)\binom{-3}{5}. Write down the coordinates of the image of PP.

(1)

(Total for Question 4 is 1 mark)

Mark scheme

Mark scheme for question 4
QuestionAnswerMarkMark scheme
4
  • P=(1,4)P'=(1,4)
1Add the vector components to the coordinates: (43,1+5)=(1,4)(4-3,-1+5)=(1,4). Therefore P=(1,4)P'=(1,4).
Q5
Tier 2 · Standard

5

A translation by (64)\binom{6}{-4} maps point QQ to Q=(2,7)Q'=(2,7). Work out the coordinates of QQ.

(2)

(Total for Question 5 is 2 marks)

Mark scheme

Mark scheme for question 5
QuestionAnswerMarkMark scheme
5
  • Q=(4,11)Q=(-4,11)
2Reverse the translation: subtract 66 from the image's xx-coordinate and add 44 to its yy-coordinate. Therefore Q=(26,7+4)=(4,11)Q=(2-6,7+4)=(-4,11).
Q6
Tier 3 · Hard

6

A translation by vector a\mathbf{a} maps P=(2,1)P=(2,-1) to (5,3)(5,3). A second translation by vector b\mathbf{b} maps (5,3)(5,3) to (1,7)(1,7). Work out a\mathbf{a}, work out b\mathbf{b}, and write down the single vector that maps PP directly to (1,7)(1,7).

(3)

(Total for Question 6 is 3 marks)

Mark scheme

Mark scheme for question 6
QuestionAnswerMarkMark scheme
6
  • a=(34)\mathbf{a}=\binom{3}{4}
  • b=(44)\mathbf{b}=\binom{-4}{4}
  • Single vector (18)\binom{-1}{8}
3a=(523(1))=(34)\mathbf{a}=\binom{5-2}{3-(-1)}=\binom{3}{4} and b=(1573)=(44)\mathbf{b}=\binom{1-5}{7-3}=\binom{-4}{4}. Successive translations add: the single vector is a+b=(344+4)=(18)\mathbf{a}+\mathbf{b}=\binom{3-4}{4+4}=\binom{-1}{8}, and indeed P=(2,1)P=(2,-1) maps directly to (21,1+8)=(1,7)(2-1,\,-1+8)=(1,7).
Q7
Tier 2 · Standard

7

Triangle TT has vertices (5,1)(-5,1), (2,1)(-2,1) and (4,4)(-4,4). After a translation, its image has vertices (1,6)(1,-6), (4,6)(4,-6) and (2,3)(2,-3) in the corresponding order. Describe the translation as a vector.

(3)

(Total for Question 7 is 3 marks)

Mark scheme

Mark scheme for question 7
QuestionAnswerMarkMark scheme
7
  • (67)\binom{6}{-7}
3Using any corresponding pair gives image minus object. For example, (1(5),61)=(6,7)(1-(-5),-6-1)=(6,-7). The other pairs give the same displacement, so the translation vector is (67)\binom{6}{-7}.
Q8
Tier 3 · Hard

8

A mapping sends A=(1,2)A=(1,-2) to A=(3,4)A'=(-3,4), B=(5,0)B=(5,0) to B=(1,6)B'=(1,6) and C=(2,3)C=(2,3) to C=(2,8)C'=(-2,8). State whether this mapping can be a translation. Give a reason.

(3)

(Total for Question 8 is 3 marks)

Mark scheme

Mark scheme for question 8
QuestionAnswerMarkMark scheme
8
  • No, AA and BB move by (46)\binom{-4}{6} but CC moves by (45)\binom{-4}{5}, so the displacement is not the same for every point.
3The displacements from AA to AA' and from BB to BB' are both (46)\binom{-4}{6}. The displacement from CC to CC' is (45)\binom{-4}{5}. A translation must move every point by the same vector, so this mapping cannot be a translation.
Q9
Tier 3 · Hard

9

Segment ABAB has endpoints A=(4,7)A=(-4,7) and B=(8,1)B=(8,-1). After a translation, the midpoint of its image ABA'B' is (9,3)(9,3). Work out the translation vector and the coordinates of AA' and BB'.

(4)

(Total for Question 9 is 4 marks)

Mark scheme

Mark scheme for question 9
QuestionAnswerMarkMark scheme
9
  • Translation vector (70)\binom{7}{0}
  • A=(3,7)A'=(3,7) and B=(15,1)B'=(15,-1)
4The midpoint of ABAB is (4+82,7+(1)2)=(2,3)\left(\frac{-4+8}{2},\frac{7+(-1)}{2}\right)=(2,3). Its displacement to (9,3)(9,3) is (70)\binom{7}{0}, which is the translation vector. Adding this vector gives A=(3,7)A'=(3,7) and B=(15,1)B'=(15,-1).
Q10
Tier 3 · Hard

10

Higher only: The line y=2x+1y=2x+1 is translated by (3k)\binom{3}{k}. Its image passes through the point (5,7)(5,7). Work out kk and write the equation of the image line.

(4)

(Total for Question 10 is 4 marks)

Mark scheme

Mark scheme for question 10
QuestionAnswerMarkMark scheme
10
  • k=2k=2
  • y=2x3y=2x-3
4The point (5,7)(5,7) on the image came from (53,7k)=(2,7k)(5-3,7-k)=(2,7-k) on the original line. Since y=2x+1y=2x+1 there, 7k=2(2)+1=57-k=2(2)+1=5, so k=2k=2. Under the translation, x=x+3x'=x+3 and y=y+2y'=y+2. Thus y2=2(x3)+1y'-2=2(x'-3)+1, which simplifies to y=2x3y'=2x'-3. Therefore the image line is y=2x3y=2x-3.

Verified exam appearances

SeriesPaperQuestionMarksCalculatorTierLinks
2024-061HQ113Non-calculatorHigherQPMS
2024-061FQ192Non-calculatorFoundationQPMS
2022-062FQ222AllowedFoundationQPMS
2022-062HQ22AllowedHigherQPMS
2019-061FQ263Non-calculatorFoundationQPMS
2019-061HQ53Non-calculatorHigherQPMS

Other points in G Geometry and measures

Want help turning this into marks?

Bring G24 or any tricky specification point, and we can work through the method and exam wording together.