Four birds land at different spots on a square field at the points P(−2,3), Q(1,3), R(−2,−4) and S(3,0). Answer the questions that follow.
a. (i) Explain which pair of birds lie on a line parallel to the y-axis and justify using their coordinates.
b. (ii) Arrange the four birds in decreasing order of their ordinates.
c. (iii) If the birds at P and R both fly vertically to the x-axis without changing their abscissas, write their new coordinates and describe how only the ordinate has changed.