1/1*3 + 1/3*5 + 1/5*7 + 1/7*9+ ...+ 1/2011*2013
= (1/2)(1 - 1/3 + 1/3 - 1/5 + ...+ 1/2011 - 1/2013)
= (1/2)(2012/2013)
= 1006/2013
1/1*3 + 1/3*5 + 1/5*7 + 1/7*9+ ...+ 1/2011*2013
= (1/2)(1 - 1/3 + 1/3 - 1/5 + ...+ 1/2011 - 1/2013)
= (1/2)(2012/2013)
= 1006/2013