The distance between the points (x1,−y1) and (−x2,y2) is ___ units.
√(x2+x1)2+(y2+y1)2
The distance between two
points (x1,y1) and (x2,y2)
is given by
√(x2−x1)2+(y2−y1)2.
Thus, the distance
between (x1,−y1) and (−x2,y2)
will be
√(−x2−x1)2+(y2−(−y1))2 =√(x2+x1)2+(y2+y1)2
[because (−x2−x1)2=(x2+x1)2]