(-1x1/2)+(-1/2x1/3)+(-1/3x1/4)+...+(-1/2013x1/2014)
问题描述:
(-1x1/2)+(-1/2x1/3)+(-1/3x1/4)+...+(-1/2013x1/2014)
答
(-1x1/2)+(-1/2x1/3)+(-1/3x1/4)+...+(-1/2013x1/2014)
=- (1-1/2+1/2-1/3+1/3-1/4+....+1/2013-1/2014)
=-(1-1/2014)
=-2013/2014
答
答:
(-1x1/2)+(-1/2x1/3)+(-1/3x1/4)+...+(-1/2013x1/2014)
=1/2-1+1/3-1/2+1/4-1/3+.+1/2014-1/2013
=-1+1/2014
=-2013/2014