(1/2—1/4+1/6—1/8+1/10+……+1/198—1/200)/1/51+1/52+……1/100=?
来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/05/17 22:54:32
(1/2—1/4+1/6—1/8+1/10+……+1/198—1/200)/1/51+1/52+……1/100=?
1/2-1/4+1/6-1/8+1/10-1/12+…+1/198-1/200
=(1-1/2+1/3-1/4+ ...+1/99-1/100)/2
=[(1+1/2+ ...+1/99+1/100)-2(1/2+1/4+ ...+1/98+1/100)]/2
=[(1+1/2+ ...+1/99+1/100)-(1+1/2+ ...+1/49+1/50)]/2
=(1/51+1/52+1/53+ ...+1/99+1/100)/2
所以原式
=(1/2)(1/51+1/52+1/53+ ...+1/99+1/100)/(1/51+1/52+1/53+…+1/100)
=1/2
=(1-1/2+1/3-1/4+ ...+1/99-1/100)/2
=[(1+1/2+ ...+1/99+1/100)-2(1/2+1/4+ ...+1/98+1/100)]/2
=[(1+1/2+ ...+1/99+1/100)-(1+1/2+ ...+1/49+1/50)]/2
=(1/51+1/52+1/53+ ...+1/99+1/100)/2
所以原式
=(1/2)(1/51+1/52+1/53+ ...+1/99+1/100)/(1/51+1/52+1/53+…+1/100)
=1/2
(1/2—1/4+1/6—1/8+1/10+……+1/198—1/200)/1/51+1/52+……1/100=?
(1/2-1/4+1/6-1/8+1/10-1/12+……+1/198-1/200)÷(1/51+1/52+1/53+1
1-1/2+1/3-1/4+1/5-1/6…+1/99-1/100)/(1/51+1/52+1/53+…+1/99+1/
1 1 1 1- —— - —— - —— - …… - ——1×4 4×7 7×10 97×100即负(1×4)分之一
【1/(1*2)+1/(3*4)+1/(5*6)+1/(7*8)+……1/(99*100)】/(1/51+1/52+……
1/2*4+1/4*6+1/6*8+……+1/198*200
1 1 1 1- —— - —— - —— - …… - —— 1×4 4×7 7×10 97×100 即负(1/1*4
1+2—3—4+6—7—8+9+10…………+2014
1、计算:1+(—2)+3+(—4)+5+(—6)+……+99+(—100).
2+4分之1+4+6分之1+6+8分之1……198+200分之1=?
200×(1-1/2)×(1-1/3)×(1-1/4)×……×(1-1/100)=?
1/2*4+1/4*6/+1/6*8+1/8*10……+1/198*200=?这道题的思路是什么