Classical examples of inequality scaling method,

Classical examples of inequality scaling method,

1+1/(1*2)+1/(2*3)+...+1/[(n-1)*n]>1+1/2^2+1/3^2+…… +1 / N ^ 2 > 1 / (1 * 2) + 1 / (2 * 3) +... + 1 / [n * (n + 1)] so: 1 + 1-1 / N > 1 + 1 / 2 ^ 2 + 1 / 3 ^ 2 + +1 / N ^ 2 > 1-1 / (n + 1) scaling method is a common method in inequality proof, and it is also a very important method