Answer:
P(2c - h, 2n - s )
Explanation:
If there are two points (x1,y1) and (x2,y2) on the coordinate plane
then midpoint is given by (x1+x2)/2 , (y1+y2)/2
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in the problem midpoint is m(c,n)
one point is Q(h,s)
let other point be P(x,y)
By using midpoint formula given above
for point P(x,y) and Q(h,s)
midpoint = (x+h)/2, (y+s)/2
also midpoint is m(c,n)
comparing m(c,n) with (x+h)/2, (y+s)/2
c = x+h/2
=> 2c = x+h
=> 2c - h = x
n = (y+s)/2
=> 2n = y+s
=> 2n - s = y
Thus, second endpoint is P(x,y) = P(2c - h, 2n - s )