Find an atlas and coordinates for a torus T^2 = S^1 X S^1

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To find an atlas and coordinates for the torus T^2 = S^1 × S^1, one can start by considering the cylinder represented as S^1 × [0, 1]. The process involves creating charts for the cylinder and then conceptualizing how to glue the ends together to form the torus. The challenge lies in transitioning from understanding the atlas for the circle to applying it to the cylinder effectively. A clear understanding of the charts for both S^1 and the cylinder is essential for constructing the atlas for the torus. Ultimately, the discussion emphasizes the need for a solid grasp of manifold theory to tackle this problem.
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Homework Statement



Find an atlas and coordinates for a torus T^2 = S^1 X S

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The Attempt at a Solution



I know that an atlas on a manifold M is a collection of charts whose domains cover M, but i am not sure how to start this one mathematically.
 
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Do you know how to find an atlas on a cylinder? If so, just do that then imagine gluing the ends of the cylinder together... what do you get for your charts?
 
Actually, no, i don't. I get that a cylinder is S1 × [0, 1], and I think I know how to find the atlas on a circle, I just feel so lost on how to apply it on a cylinder.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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