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प्रश्न
The point P(a, b) is first reflected in the origin and then reflected in the y-axis to P’. If P’ has co-ordinates (4, 6); evaluate a and b.
उत्तर
MO (a, b) = (–a, –b)
My (–a, –b) = (a, –b)
Thus, we get the co-ordinates of the point P’ as (a, –b). It is given that the co-ordinates of P’ are (4, 6).
On comparing the two points, we get, a = 4 and b = –6
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संबंधित प्रश्न
A point P is reflected in the x-axis. Co-ordinates of its image are (–4, 5). Find the co-ordinates of the image of P under reflection in the y-axis.
S' is the image of S under reflection in the origin. If the co-ordinates of S are (2,-5), write the co-ordinates of S'.
A point P is reflected in the x-axis. Co-ordinates of its image are (8, −6). Find the co-ordinates of P. Find the co-ordinates of the image of P under reflection in the y-axis.
A triangle ABC lies in the co-ordinate plane. The co-ordinates of its vertices are A (2, 3), B ( 4,-4) and C (6 ,-7). This triangle is reflected in the line y=O onto LA'B'C'. LA'B'C' is then reflected in the origin ontolA"B"C". Write down the co-ordinates of LA'B'C' and LA "B" C".
Point A ( 4,-1) is reflected as A' in the line x= 1. Point B on reflection in the line y=3 is mapped as B' (6,-1). Write the co-ordinates of A' and B. Write the co-ordinates of mid.-ooint of the line sgment A' B'.
State the co-ordinates of the following point under reflection in x-axis:
(–5, 4)
Point A(4, – 1) is reflected as A’ on Y-axis. Point B on refletion on X-axis is mapped as B’ (- 2, 5).
(i) Write the co-ordinates of A’.
(ii) Write the co-ordinates of B.
(iii) Write the co-ordinates of the middle point
M of the segment A’B.
(iv) Write the co-ordinates of the point of reflection A” of A on X-axis.
Use a graph paper to answer the following questions. (Take 1 cm = 1 unit on both axis):
(i) Plot A (4, 4), B (4, – 6) and C (8, 0), the vertices of a triangle ABC.
(ii) Reflect ABC on the y-axis and name it as A’B’C’.
(iii) Write the coordinates of the images A’, B’ and C’.
(iv) Give a geometrical name for the figure AA’ C’B’ BC.
(v) Identify the line of symmetry of AA’ C’ B’ BC.
Use graph paper to answer the following questions. (Take 2 cm = 1 unit on both axis).
(i) Plot the points A (- 4, 2) and B (2, 4).
(ii) A’ is the image of A when reflected in the y-axis. Plot it on the graph paper and write the coordinates of A’.
(iii) B’ is the image of B when reflected in the line AA’. Write the coordinates of B’.
(iv) Write the geometric name of the figure ABA’B’.
(v) Name a line of symmetry of the figure formed.
