An object is moving counter-clockwise along a circle with the centre at the origin. At \(t=0\) the object is at point \(A(0,5)\) and at \(t=2\pi\) it is back to point \(A\) for the first time.

Using high school algebra and geometry, and knowing just one rational point on a circle or elliptic curve, we can locate infinitely many others. You’re sitting at the end of a long conference table, ...

Any point P with coordinates (\(x, y\)) on the circumference of a circle can be joined to the centre (0, 0) by a straight line that forms the hypotenuse of a right angle triangle with sides of length ...