Given:-
A circle with centre (2,−3) and AB is the diameter of circle with B(1,4).
To find:- Coordinate of point A.
Let (x,y) be the coordinate of A.
Since AB is the diameter of the circle, the centre will be the mid-point of AB.
now, as centre is the mid-point of AB.
x-coordinate of centre =x+12
y-coordinate of centre =y+42
But given that centre of circle is (2,−3).
Therefore,
x+12=2⇒x=3
y+42=−3⇒y=−10
Thus the coordinate of A is (3,−10).
Hence the correct answer is (3,−10).