Question

If AB has endpoint A(2,13) and midpoint (10,-1) then give the coordinate of B.

Answer 1

Answer:
So coordinates of B (18,-15)

Explanation:

Given: Line coordinates P(10,-1)

A-------------------------------------------B (2,13) (x, y)The point P(x', y') divides AB in 1:1 ratio

=m:nSo from formula:x'

=(mx1 + nx2)/(m+n) and y'

= (my1+ny2)/(m+n) where (x',y')

=(10,-1), m:n

=1:1 and (x1, y1)

=(2,13), (x2,y2)=(x,y)

Put the values in the formula:

10 = 1(2)+1(x)/1+1 = (2+x)/2

=>20=2+x from cross multiplication

=>x=20-2=18 from transposition

=>x=18

-1=1(13)+1(y)/1+1 =(13+y)/2

=>-2=13+y from cross multiplication

=>y=-2-13=-15 from transposition

=>y=-15