c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d  = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

c = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 , d = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 tính c-d

Tìm C, D

C = 2005/2 + 2005/3+ 2005/4+....+ 2005/2005 

D = 2006 / 1 + 2006 / 2 + 2006 / 3 +....+ 4009 / 2004 

so sánh 2005^2017+1/2005^2008+2 và 2005^2018+4?2005^2019+3

 2008+2007/2+2006/3+2005/4+2005/5+........................3/2006+2/2007+1/2008

1/2+1/3+1/4+1/5+....................+1/2009

 2008+2007/2+2006/3+2005/4+2005/5+........................3/2006+2/2007+1/2008

1/2+1/3+1/4+1/5+....................+1/2009

Tính: 

S = \(\frac{2}{2005+1}\)+ \(\frac{2^2}{2005^2+1}\)+ \(\frac{2^3}{2005^{2^2}+1}\)+ \(\frac{2^4}{2005^{2^3}+1}\)+ ...+ \(\frac{2^{n+1}}{2005^{2^n}+1}\)+ ...+ \(\frac{2^{2006}}{2005^{2^{2005}}+1}\)

Tính: S

S= \(\frac{2}{2005+1}\) + \(\frac{2^2}{2005^2+1}\)+ \(\frac{2^3}{2005^{2^2}+1}\)+ \(\frac{2^4}{2005^{2^3}+1}\)+ .... + \(\frac{2005^{2006}}{2005^{2^{2005}}+1}\)+ .... + \(\frac{2^{n+1}}{2005^{2^n}+1}\)