How to find the coordinates of the reflection of a point in yaxis?
To find the coordinates in the adjoining figure, yaxis represents the plane mirror. M is the any point whose coordinates are (h, k) in the rectangular axes in first quadrant.
Observe when point M is reflected in yaxis, the image M' is formed in the second quadrant whose coordinates are (h, k).
Thus we conclude that when a point is reflected in yaxis, then the ycoordinate remains same and then xcoordinate become negative.
Thus, the image of M (h, k) is M' (h, k).
Rules to find the reflection of a point in the yaxis:
(i) Change the sign of abscissa i.e., xcoordinate.
(ii) Retain the ordinate i.e., ycoordinate.
Examples to find the coordinates of the reflection of a point in yaxis:
1. Write the coordinates of the image of the following points when reflected in yaxis.
(i) (4 , 3)
(ii) (3, 5)
(iii) (1, 6)
(iv) (5, 7)
Solution:
(i) The image of (4 , 3) is (4 , 3).
(ii) The image of (3, 5) is (3, 5).
(iii) The image of (1 , 6) is (1, 6).
(iv) The image of (5, 7) is (5, 7).
2. Find the reflection of the following in yaxis.
(i) P
(7, 9)
(ii) Q
(3, 6)
(iii) R
(4, 8)
(iv) S (5, 7)
Solution:
(i) The image of P (7, 9) is P' (7, 9).
(ii) The image of Q (3, 6) is Q' (3, 6).
(iii) The image of R (4, 8) is R' (4, 8).
(iv) The image of S (5, 7) is S' (5, 7).
Solved example to find the reflection of a parallelogram in yaxis:
3. Draw the image of the parallelogram PQRS having its vertices P (2, 5); Q (2, 1); R (5, 4); S (5, 2) in yaxis.
Solution:
Plot the points P (2, 5); Q (2, 1); R (5, 4); S (5, 2) on the graph paper. Now join PQ, QR, RS and SP to get a parallelogram.
When reflected in yaxis, we get P' (2, 5); Q' (2, 1); R' (5, 4); S' (5, 2). Now join P'Q', Q'R', R'S' and S'P'.
Thus we get the parallelogram P'Q'R'S as the image of the parallelogram PQRS in yaxis.
Solved example to find the reflection of a rectangle in yaxis:
4. The coordinate of the rectangle PQRS having its vertices P (4, 5), Q (1, 5), R (1, 2), S (4, 2). Draw the image of the figure when reflected in yaxis.
Solution:
Plot the coordinates of
the points P (4,
5), Q (1, 5), R (1, 2), S (4, 2) on the graph paper.
Join PQ, QR, RS and SP to get a rectangle.
When reflected in yaxis we get;
The image of P (4, 5) is P' (4, 5)
The image of Q (1, 5) is Q' (1, 5)
The image of R (1, 2) is R' (1, 2)
The image of S (4, 2) is R' (4, 2)
Plot the point P', Q', R' and S' on the same graph paper. Now join P'Q', Q'R', R'S' and S'P'.
Thus we get the rectangle P'Q'R'S as the image of the rectangle PQRS when reflection in yaxis.
Note: Point M (h, k) has its image M' (h, k) when reflected in yaxis.
Thus, we conclude that when the reflection of a point in yaxis:
● Related Concepts
● Order of Rotational Symmetry
● Reflection of a Point in xaxis
● Reflection of a point in origin
● Rotation
● 90 Degree Clockwise Rotation
● 90 Degree Anticlockwise Rotation
7th Grade Math Problems
8th Grade Math Practice
From Reflection of a Point in yaxis to HOME PAGE
Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.

New! Comments
Have your say about what you just read! Leave me a comment in the box below. Ask a Question or Answer a Question.