1)试比较下列各组数的大小 -1/2与-2/3,-2/3与-3/4,-3/4与-4/5,-4/5与-5/6 (2)你能模仿上面(1)得出-n+1/njlhloui
问题描述:
1)试比较下列各组数的大小 -1/2与-2/3,-2/3与-3/4,-3/4与-4/5,-4/5与-5/6 (2)你能模仿上面(1)得出-n+1/n
jlhloui
答
-1/2>-2/3;-2/3>-3/4;-3/4>-4/5;
推出:-n+1/n>-n/n+1
答
-1/2-n+1/n
答
-n+1/n =-1+1/n
所以随着n的增大,1/n变小,-1+1/n变小
即 -1/2与-2/3,-2/3与-3/4,-3/4与-4/5,-4/5与-5/6 逐渐变小