将每一项都列项,
1/1*3=1/2(1/1-1/3)
1/3*5=1/2(1/3-1/5)
1/5*7=1/2(1/5-1/7)
……
1/2001*2003=1/2(1/2001-1/2003)
所以,
1/1*3+1/3*5+1/5*7+…+1/2001*2003
=(1-1/2003)÷2=1001/2003
将每一项都列项,
1/1*3=1/2(1/1-1/3)
1/3*5=1/2(1/3-1/5)
1/5*7=1/2(1/5-1/7)
……
1/2001*2003=1/2(1/2001-1/2003)
所以,
1/1*3+1/3*5+1/5*7+…+1/2001*2003
=(1-1/2003)÷2=1001/2003