Steply

Find the midpoint of the line joining (−2, 3) and (6, 7).

Step by step, with the reason for every step · IGCSE Maths Core Paper 3 · IGCSE Maths

Step by step

The question

Question: find the midpoint of (−2, 3) and (6, 7).

(−2, 3) and (6, 7)

1 Plot the points

Draw the grid.

Put both points on the grid: (−2, 3)

and (6, 7).

Join them with a straight line.

We want its middle.

2 Middle of the x's

The midpoint is halfway across.

Halfway between two numbers: add them, then divide by 2.

x = −2 + 62

−2 plus 6 is 4.

x = 42

4 divided by 2 is 2.

So x = 2.

x = 2

Is 2 really in the middle?

From −2, a jump of 4 gives 2.

From 2, 4 more gives 6.

The same jump from each end.

So adding and halving finds the middle.

−2 + 4 = 2
2 + 4 = 6

3 Middle of the y's

Now the y's: the same.

Add them, then divide by 2.

y = 3 + 72

3 plus 7 is 10.

y = 102

10 divided by 2 is 5.

So y = 5.

y = 5

4 The midpoint

So the midpoint is M = (2, 5).

M = (2, 5)

Put M on the grid.

It sits on the line, right in the middle.

5 Check

Let's check on the grid.

From (−2, 3) to M:

we go right 4, up 2.

(−2, 3) → M: right 4, up 2

From M to the other point:

we go right 4, up 2.

The same moves.

So M is exactly in the middle!

M → (6, 7): right 4, up 2

Let's look back.

First: plot the points.

Then: middle of the x's.

Then: middle of the y's.

Then: the midpoint.

Last: check.

Answer
M = (2, 5)

Your turn

Try this one yourself, then check your answer:

Find the midpoint of (−2, 5) and (4, 7)
Show the answer
M = (1, 6)

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