What is the midpoint formula for two points (x1, y1) and (x2, y2)?

What is the midpoint formula for two points (x1, y1) and (x2, y2)?

• A. ((x1 + x2)/2, (y1 + y2)/2)
• B. ((x1 - x2)/2, (y1 - y2)/2)
• C. ((x1 + y2)/2, (y1 + x2)/2)
• D. ((x1 x2)/2, (y1 y2)/2)

Answer: (A)

The midpoint is the point exactly halfway between two points, so you treat each coordinate separately. The x-coordinate of the midpoint is halfway between x1 and x2, which is (x1 + x2)/2. The y-coordinate is halfway between y1 and y2, which is (y1 + y2)/2. Put together, the midpoint is ((x1 + x2)/2, (y1 + y2)/2). This makes sense because you’re averaging the two x-values to land midway on the horizontal axis and averaging the two y-values to land midway on the vertical axis. For example, between (0,0) and (2,6) the midpoint is ((0+2)/2, (0+6)/2) = (1,3). The other forms either halve a difference, mix coordinates incorrectly, or multiply coordinates, none of which give the point halfway along the segment.

The midpoint is the point exactly halfway between two points, so you treat each coordinate separately. The x-coordinate of the midpoint is halfway between x1 and x2, which is (x1 + x2)/2. The y-coordinate is halfway between y1 and y2, which is (y1 + y2)/2. Put together, the midpoint is ((x1 + x2)/2, (y1 + y2)/2). This makes sense because you’re averaging the two x-values to land midway on the horizontal axis and averaging the two y-values to land midway on the vertical axis. For example, between (0,0) and (2,6) the midpoint is ((0+2)/2, (0+6)/2) = (1,3). The other forms either halve a difference, mix coordinates incorrectly, or multiply coordinates, none of which give the point halfway along the segment.