Question

cho N = 1/2²+1/3²+1/4²+...+1/2009²+1/2010²

CM: N < 1

Answer 1

1/2²<1/1*2=1/1-1/2

1/3²<1/2*3=1/2-1/3

1/4²<1/3*4=1/3-1/4

1/2010²<1/2009*2010=1/2009-1/2010

1/2²+1/3²+1/4²+...+1/2010²<1/1-1/2+1/2-1/3+1/3-1/4+...+1/2009-1/2010

1/2²+1/3²+1/4²+...+1/2010<1/1-1/2010<1 (dfcm)

Answer 2

k mình nha