Exercises:Mond - Topology - 1/Pictures/Q6P1 - 1
From Maths
Take -1 to any point on the circle (we pick the south pole in this diagram), then go around the circle at a constant speed such that by f(1) one has done a full revolution and is back at the starting point.
The right-hand-side is intended to demonstrate that the interval (−1,1) to the circle without the south-pole is bijective, ie it is injective and surjective, so the diagram on the left is "almost injective" in that it is injective everywhere except that it maps −1 and 1 both to the south pole.
As required
The right-hand-side is intended to demonstrate that the interval (−1,1) to the circle without the south-pole is bijective, ie it is injective and surjective, so the diagram on the left is "almost injective" in that it is injective everywhere except that it maps −1 and 1 both to the south pole.
As required
