Question
Find the midpoint of the line segment joining the points and .
Solution — Step by Step
The midpoint of a segment joining and is:
This is just the average of the x-coordinates and the average of the y-coordinates — nothing more.
Let and .
Labelling first prevents sign errors, which is where most marks are lost in board exams.
The midpoint of the segment is M = (1, 1).
Why This Works
The midpoint formula is really just the arithmetic mean applied to coordinates. If you have two values on a number line, their average gives the point exactly halfway between them. We apply that idea separately to x and y.
Geometrically, you can verify: the distance from to equals the distance from to . Both come out to , confirming sits exactly in the middle.
This question has appeared in NCERT Exercise 7.2 and is a guaranteed 2-marker in CBSE Class 10 boards. The formula is also the foundation for Section Formula questions — get comfortable with this before moving there.
Alternative Method
You can verify the midpoint by checking equal distances using the distance formula.
Distance from to :
Distance from to :
Since , the point divides the segment equally — confirmed as the midpoint. In exams, skip this verification unless explicitly asked.
Common Mistake
Students write — treating as , or misreading it as . The negation applies only to the 2, not to the sum. Always compute the numerator first before dividing: , then .
If both coordinates of the midpoint come out as whole numbers (like they do here), that’s a good sign your arithmetic is clean. NCERT problems are designed with integer answers — a decimal result mid-calculation usually signals a sign error.