2010·(1-1/2)·(1-1/3)·(1-1/4)·…·(1-1/2010)
2010·(1-1/2)·(1-1/3)·(1-1/4)·…·(1-1/2010)
1、(1+3+5+···+2009+2011)-(2+4+6+···+2010+2012)
(1)2010×(1-1/2)×(1-1/3)×(1-1/4)×·········×(1-1/2009)×(1-1/20
(-1)+2+(-3)+4+······+(-2009)+2010+(-2011)=__________________
计算 1*2/1+2*3/1+3*4/1+············+2009*2010/1
(1+1/2)(1-1/3)(1+1/4)(1-1/5)··········(1-1/2005)(1+1/2006)=_
计算(+1)+(-2)+(+3)+(-4)+······+(-100)+(+101)+(-102)
计算:(-1+1/100)*(-1+1/101)*(-1+1/102)*···*(-1+1/2010)
计算 1-2+3-4+5-6+····+(-1)^n+1*n
根据1+2+3+4+······+n=n(n+1)/2 计算2+4+6+····+200
求证;1+1/2+1/3+······+1/k≧(2k)/(k+1)
1+(-2)+3+(-4)···········+99-100等于多少