霜冷
幼苗
共回答了17个问题采纳率:88.2% 举报
1/(x-1)-1/(x+1)-2/(x^2+1)-4/(x^4+1)
=2/(x^2-1)-2/(x^2+1)-4(x^4+1)
=4/(x^4-1)-4/(x^4+1)
=8/(x^8-1)
2/(x+1)(x+3)=[(x+3)-(x+1)]/(x+1)(x+3)=1/(x+1)-1/(x+3)
所以原式=1/(x+1)-1/(x+3)+1/(x+3)-1/(x+5).+1/(x+2007)-1/(x+2009)
=1/(x+1)-1/(x+2009)
a2=1-1/x=(x-1)/x
a3=1-x/(x-1)=-1/(x-1)
a4=1-(x-1)/(-1)=1+x-1=x
a5=a2=(x-1)/x
以3为周期a2000=a2=(x-1)/x
1年前
1