⑩天掌 Teaching Plan on Advanced Mathematics 再设函数x=g(t),y=y()都可导,且()≠0, 由复合函数及反函数的求导法则得 dy dy dt dy 1_y'( dt dx dt dx '(t) dt 小y 即 dy dt dx dTianjin Polytechnic University Teaching Plan on Advanced Mathematics 再设函数x = (t), y =(t)都可导,且(t)  0, 由复合函数及反函数的求导法则得 dx dt dt dy dx dy =  dt dt dx dy 1 =  ( ) ( ) t t     = dt dx dt dy dx dy 即 =