The correct option is A √(x1+x2)2+(y1+y2)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
[∵(−x2−x1)2=(x2+x1)2]
=√(x1+x2)2+(y1+y2)2