Answer:
(q,0)
Explanation:
See the diagram given.
It is clear from the coordinates of the points given that point C (0,r) lies on the Y-axis and point E (-q,o) lies on the X-axis. Hence, point D must be on the X-axis.
ΔCDE being an isosceles triangle, the origin of the coordinate axes will be on the DE line and it will be at the midpoint of DE.
Therefore, ΔCDE will be symmetric with respect to the Y-axis and the coordinates of point D will be (q,0). (Answer)