• wholookshere@lemmy.blahaj.zone
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      2 hours ago

      Only true in Cartesian coordinates.

      A straight line in polar coordinates with the same tangent would be a circle.

      EDIT: it is still a “straight” line. But then the result of a square on a surface is not the same shape any more.

      • ltxrtquq@lemmy.ml
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        19 minutes ago

        A straight line in polar coordinates with the same tangent would be a circle.

        I’m not sure that’s true. In non-euclidean geometry it might be, but aren’t polar coordinates just an alternative way of expressing cartesian?

        Looking at a libre textbook, it seems to be showing that a tangent line in polar coordinates is still a straight line, not a circle.