wobuhuizaijisuanjishangxieshuxuefuhao,zhihaoshuoguochengle!
此题即{1+1/3+1/5+1/7..+1/999-(1/2+1/4+
1/6..+1/1000)}+1/1001
即:2n-1fenzhiyide和减去2nfenzhiyidehe,
恩是500.
用等差数列公式那章的三个补充公式求得.
wobuhuizaijisuanjishangxieshuxuefuhao,zhihaoshuoguochengle!
此题即{1+1/3+1/5+1/7..+1/999-(1/2+1/4+
1/6..+1/1000)}+1/1001
即:2n-1fenzhiyide和减去2nfenzhiyidehe,
恩是500.
用等差数列公式那章的三个补充公式求得.