the coordinate of the midpoint of a line segement AB are (-2,4) if the coordinate of point A are (7,10) what are the coordinates of B?
how can i solve this problem i tried using the midpoint formula but it doesnt work
Hi zelda,
the midpoint formula ought to work easily enough.
You can simply say....
the x co-ordinate of the midpoint is halfway between the x co-ordinates
of the points on the line.
So -2 is halfway between 7 and another x.
-2 is 9 away from 7.
The other value 9 away from -2 is -11.
So -2 is halfway between -11 and 9.
Also 4 is halfway between 10 and -2
The other point is (-11,-2).
Using the midpoint formula, which is
"the x midpoint is the average of the x values"
"the y midpoint is the average of the y values".
$\displaystyle \frac{x_1+x_2}{2}=-2$
$\displaystyle x_1+x_2=-2(2)=-4$
$\displaystyle x_1=-4-x_2=-4-7=-11$
$\displaystyle \frac{y_1+y_2}{2}=4$
$\displaystyle y_1+y_2=4(2)=8$
$\displaystyle y_1=8-y_2=8-10=-2$