Question

one of the endpoints of cd is at the point (3,-6) .if the midpoint m, of cd is at the point (-3,9) find the coordinates of the other endpoint

Answer 1

we know that

The formula to calculate the midpoint between two points is equal to

`M((x1+x2)/(2),(y1+y2)/(2))`

In this problem we have

M(-3,9)

(x1,y1)=(3,-6)

(x2,y2)=?

substitute the given values in the formula

`(-3,9)=((3+x2)/(2),(-6+y2)/(2))`

Find the x1 coordinate

we have

-3=(3+x2)/2

3+x2=-6

x2=-6-3

x2=-9

Find the y2 coordinate

we have

9=(-6+y2)/2

y2=18+6

y2=24

therefore

the coordinates of the other endpoint are (-9,24)