a.b满足lab-2l+l1-bl=0,求1/ab+1/(a+1)(b+2)++2)+.+1/(a+2008)(b+2008)的值如题

a.b满足lab-2l+l1-bl=0,求1/ab+1/(a+1)(b+2)++2)+.+1/(a+2008)(b+2008)的值如题 非零向量a,b满足la+bl=lbl 则l2bl>la+2bl为什么?证明：非零向量a,b满足la+bl=lbl 则l2bl>la+2bl 已知lab+2l+la+1l=0,求1/(a-1)(b+1)+1/(a-2)(b+2)...+1/(2-2004)(b+2004) 以知A＞0,B＜0,简化la+bl-la-bl+l-a-bl-lb-al 过点P(0,-1)的直线L与抛物线X^2=4Y交于A,B两点.L1与L2为抛物线X^2=4Y在A,BL两处的切线,M,N分别是L1,L2与直线Y=-1的焦点.比较PM与PN的大小,并说明理由. 当向量a,b满足什么关系时,la+bl=la-bl 若lab-2l+(b-1)²=0,求“1/ab+1/(a+1)(b+1)+…+1/(a+2012)(b+2012)”怎么做? 设向量a,b满足lal=lbl=1,及l3a-2bl=根号7,求a,b夹角的大小,求l3a+bl的值 已知向量a,b满足lal=2,lbl=1,la-bl=2.求a*b的值.求la+bl的值 已知lab-2l与(b十1)的平方=0,则(a一b)2012的平方等于多少? 若非零向量a,b满足la+bl=la一bl,求a,b的夹角 已知lab+2l+la+1l+0,则代数式1/（a-1)(b+1) +1/（a-2)(b+2)+^+1/(a-2009)(b+2009) 设向量a,b满足lal=lbl=1,a.b=-1/2,则la+2bl= 已知lab-2l+la-2l=0,求1/ab+1/(a+1)(b+1)+1/(a+2)(b+2)+```+1/(a+2006)(b+2006)的值 已知向量a,b满足lal=lbl=la-bl=1则la+bl=? 若向量a、b满足：lal=3,la+bl=5,la-bl=5,求lbl 如果la-1l+lab-2l=0.求1/ab+1/(a+1)(b+1)+...+1/(a+2004)(b+2004) 已知有理数a.b.c在数轴上的位置如图,求la+bl-lb+1l-la-cl-l1-cl的值 ---b---a------_1------0--c--1