1/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×2012

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/16 19:44:29
1/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×20121/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×20121/2×5+1/5×8+

1/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×2012
1/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×2012

1/2×5+1/5×8+1/8×11+.+1/2006×2009+1/2009×2012
=1/3×(1/2-1/5)+1/3×(1/5-1/8)+1/3×(1/8-1/11)+……+1/3×(1/2009-1/2012)
=1/3×(1/2-1/5+1/5-1/8+1/8-1/11+……+1/2009-1/2012)
=1/3×(1/2-1/2012)
=335/2012