The endpoints of AB are A(-3,-1) and B(5,1). What is the y-coordinate of the midpoint of AB?

Answer 1

The midpoint is exactly what it sounds like it should be, it's the middle! And the Y-coordinates are simply the second number given in the ordered pair of numbers for coordinate points.

So to solve this problem you just need to find the middle point between the y-coordinates of A(1,-1) and B(5,1). That means we need the middle number between -1 and 1.

If you can see/count that the middle number is 0, great you are done! But don't worry, we also can use the midpoint formula to calculate the answer too.

The midpoint formula is just the average value (or the middle of the two points), so we would use this formula (Ya+Yb)/2 to get the midpoint. Plugging in for A(1,-1) and B(5,1) into our formula gets us:

(-1+1)/2

=0/2

=0.

So 0 is indeed the y-coordinate midpoint value!

Answer 2

Hi Jared,

Use the midpoint formula: Midpt. = ((x1 + x2)/2), (y1 + y2)/2)

You are interested only in the y-coordinate, so:

Midpt. (y) = (-1 + 1)/2 =0

y-coordinate of midpoint is 0.

I hope this helps.