1.(1-1/2+1/3-1/4+...+1/2011-1/2012)/(1/(1+2013)+1/(2+2014)+....1/ï¼1006+3018ï¼)
2.一个负数的负数负数负数平方是1,这个负数是源码源码多少?
(1-1/2+1/3-1/4+...+1/2011-1/2012)/(1/(1+2013)+1/(2+2014)+....1/ï¼1006+3018ï¼)
å çååé¨å,æå®æç §æ£è´åæ两å,第ä¸å1+1/3+1/5+1/7+...+1/+1/,ç¨Aæ¥è¡¨ç¤º
第äºå-1/2-1/4-1/6-..-1/-1/,ç¨Bæ¥è¡¨ç¤º,对Bä¸çæ¯ä¸ä¸ªè´æ°é½å¯ä»¥æ¢ç§è¡¨è¾¾æ¹å¼
å³-1/2=1/2-1 -1/4=1/4-1/2 -1/6=1/6-1/3 .... -1/=1/-1/ 1/=1/-1/;
åB=1/2-1 +1/4-1/2 + 1/6-1/3 +...+1/-1/ +1/-1/
=1/2+1/4+1/6+...1/+1/ -(1+1/2+1/3+...1/+1/)
ç¨B1æ¥è¡¨ç¤º1/2+1/4+1/6+...1/+1/,,B2æ¥è¡¨ç¤º(1+1/2+1/3+...1/+1/)
åB=B1-B2
èA+B1=1+1/3+1/5+1/7+...+1/+1/ + 1/2+1/4+1/6+...+1/+1/
=1+1/2+1/3+.....1/+1/+1/+1/+.....+1/+1/=Cç¨Cæ¥è¡¨ç¤º
A+B1-B2=C-B2=1/+1/+.....+1/+1/ ç¨Dæ¥è¡¨ç¤º æ以åå=D
åçåæ¯:
ååæ¯å¯åæ 1/+1/+1/+....+1/,æåºå ¬å å1/2å¯å¾
=1/2(1/+1/+.....+1/+1/)
=1/2*D
æ以åå/åæ¯=D/(1/2D)=2
一个负数的平方是1,这个负数是码算淘宝首页店铺源码多少?
1-1/2=1/2, 1/3-1=-2/3, ......, 1-1/=/, 1/-1=-/
可见,从1/2到-/,负数负数负数共项,源码源码gprs web源码且其中偶数项为负,码算源码比对 补丁奇数项为正,负数负数负数所以,源码源码共个负数
偶数个负号相乘等于正号
所以,码算原式等于所有负号去掉后正数相乘,负数负数负数即
源码源码原式=1/2*2/3*3/4*......*/=1/
源码源码