Advertisements
Advertisements
Question
The point (–5, 0) on reflection in a line is mapped as (5, 0) and the point (–2, –6) on reflection in the same line is mapped as (2, –6).
- Name the line of reflection.
- Write down the co-ordinates of the image of (5, –8) in the line obtained in (a).
Solution
a. We know that reflection in the line x = 0 is the reflection in the y-axis.
It is given that:
Point (–5, 0) on reflection in a line is mapped as (5, 0).
Point (–2, –6) on reflection in the same line is mapped as (2, –6).
Hence, the line of reflection is x = 0.
b. It is known that My (x, y) = (–x, y) Co-ordinates of the image of (5, –8) in the line x = 0 are (–5, –8).
APPEARS IN
RELATED QUESTIONS
State the co-ordinates of the following point under reflection in the line y = 0:
(–3, 0)
The triangle ABC, where A is (2, 6), B is (-3, 5) and C is (4, 7), is reflected in the y-axis to triangle A’B’C’. Triangle A’B’C’ is then reflected in the origin to triangle A”B”C”.
(i) Write down the co-ordinates of A”, B” and C”.
(ii) Write down a single transformation that maps triangle ABC onto triangle A”B”C”.
Find the image of point (4, -6) under the following operations:
(i) Mx . My (ii) My . Mx
(iii) MO . Mx (iv) Mx . MO
(v) MO . My (vi) My . MO
Write down a single transformation equivalent to each operation given above. State whether:
(a) MO . Mx = Mx . MO
(b) My . MO = MO . My
State the co-ordinates of the images of the following point under reflection in the origin:
(-1,-4)
State the co-ordinates of the images of the following point under reflection in the origin:
(9,-9)
Find the co-ordinates of the images of the following under reflection in the origin:
(3, -7)
Find the co-ordinates of the images of the following under reflection in the origin:
(0, 0).
Point A (2, -4) is reflected in origin as A’. Point B (- 3, 2) is reflected on X-axis as B’.
(i) Write the co-ordinates of A’.
(ii) Write the co-ordinates of B’.
(iii) Calculate the distance A’B’.
Give your answer correct to 1 decimal place, (do not consult tables).
The image of triangle OXY under reflection in the origin, O is the triangle OX1Y1, where X1(-3, -4) is the image of X and Y1, (0, -5) is the image of Y.
(i) Draw a diagram to represent this information and write down the co-ordinates of X and Y.
(ii) What kind of figure is the quadrilateral XYX1Y1? Give reason for your answer. State, with a reason, whether the figure XYX1Y1 has any lines of symmetry.
(iii) Find the co-ordinates of X2, the image of X under reflection in the origin followed by reflection on the Y-axis.
(iv) Find the co-ordinates of Y2, the image of Y under reflection on the X-axis followed by reflection in the origin.
Use graph paper for this question.
The points A (2, 3), B (4, 5) and C (7, 2) are the vertices of A ABC.
- Write down the coordinates of A’, B’, C’ if Δ A’B’C’ is the image of Δ ABC, when reflected in the origin.
- Write down the co-ordinates of A”, B”, C” if A” B” C” is the image of Δ ABC, when reflected in the x-axis.
- Mention the special name of the quadrilateral BCC” B” and find its area.
