1+2t-t²＝1→t＝0或2;
4t²＝16→t＝2或-2.
∴t＝2.
k＝dy/dx＝8t/(2-2t)＝4t/(1-t)＝4×2/(1-2)＝-8.
故切线为y-16＝-8(x-1)→8x+y-24＝0;
法线方程y-16＝(1/8)(x-1)→x-8y+127＝0.