难!有人说数学难!是否难于上青天?但时至今日,人们已能在月上徘徊,空间漫步.人类总是不满足于现在,从“难”走向更难,要向宇宙空间飞去!实际上,有志者天下无难事,畏难者寸步不敢移.就登天来说:九十九难中,数学仅算其一难,但却是必不可少的工具之一.从牛顿力学一开始就为计算卫星轨道写下了方程.牛顿以前,算星球轨道知其然,而不知其所以然,的确很难.有了万有引力定律,至今人造卫星轨道的计算早已不在话下,时代发展了,难的不难了,人类总是 Difficult to say Some people say math difficult! Is it difficult on the sky? But up to now, people have been wandering in the sky, space walk. Mankind is always not satisfied with the present, from “hard ” to more difficult to space In fact, there is no man in the world without any difficulty, afraid of those who can not move .On the sky: ninety-nine difficult, mathematics is only a hard one, but it is an indispensable tool. Newtonian mechanics began to write equations for the calculation of satellite orbit from the very beginning. Indeed, Newton’s calculation of orbital orbit was so difficult that it was indeed hard to know the orbit of the planet, Developed, difficult is not difficult, human always