For x>0, (1/x^2) - 1/(x+1)^2 >= 2/(x+1)^3 and therefore, for any positive integer n:

(1/n^2) - 1/(n+1)^2 >= 2/(n+1)^3

Prove this fact using the Mean Value Theorem.

Well, I suppose we should start by making f(x)=2/(x+1)^3

and so the MVT says that there is some c so that

f'(c)=f(t)-f(0)/(t-0) and then f'(c)*t+f(0)=f(t), but I don't know, I'm confused. This is how most of the other proofs in the text start off....