y=x^10/(1-x)
=y=ï¼x^10-1+1ï¼/(1-x)
=-ï¼x^9+x^8+...+x+1ï¼+1/(1-x)
å 为åé¢ç
å¤é¡¹å¼-ï¼x^9+x^8+...+x+1ï¼æé«9次æ¹ï¼æ以
10é¶å¯¼æ°=0
æ以
åªè¦ç®ï¼1/(1-x)ç10é¶å¯¼æ°å³å¯
è¿æ¯æå
¬å¼çï¼
y'=1/(1-x)²
y''=2!/(1-x)³
ãããã
æ以
y^(10)= 10ï¼/(1-x)^11