Question

One end of the diameter of a circle is (–2, 5). Find the co-ordinates of the other end of it, if the centre of the circle is (2, –1).

Answer 1

We know that the centre is the mid-point of diameter.

Let the required co-ordinates of the other end of mid-point be (x, y).

∴ `(2, -1) = ((-2 + x)/2, (5 + y)/2)`

`=> 2 = (-2 + x)/2` and `-1 = (5 + y)/2`

`=>` 4 = –2 + x and –2 = 5 + y

`=>` 6 = x and –7 = y

Thus, the required co-ordinates are (6, −7).