: 1440 (Sir Isaac Newton) 25 1642 20 1727, 4 1643 31 1727 . . . .::::::: :::::: ݔ . :::::: :::::::: 9.8 / . :::::: :::::: :::: ::::: = x 1 1 / ::::: ::::::: 1 2 2 1 : ... ... ... ... ... ... ...
.. : : :