I started working with it (using n+1), but the algebra just doesn't seem to be coming together. Assistance would be greatly appreciated.
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Base Case (n = 1):
1/1^2 = 1 = 2 - 1/1.
Inductive Step:
Assuming that 1 + 1/2^2 + ... + 1/k^2 ≤ 2 - 1/k:
1 + 1/2^2 + ... + 1/k^2 + 1/(k+1)^2
= [1 + 1/2^2 + ... + 1/k^2] + 1/(k+1)^2
≤ (2 - 1/k) + 1/(k+1)^2, by inductive hypothesis
It suffices to show that
-1/k + 1/(k+1)^2 ≤ 1/(k+1) for all k > 0.
This is true
<==> -(k+1)^2 + k ≤ k(k+1), clearing fractions
<==> -(k+1)^2 ≤ k^2, which is clearly true for k > 0.
I hope this helps!
1/1^2 = 1 = 2 - 1/1.
Inductive Step:
Assuming that 1 + 1/2^2 + ... + 1/k^2 ≤ 2 - 1/k:
1 + 1/2^2 + ... + 1/k^2 + 1/(k+1)^2
= [1 + 1/2^2 + ... + 1/k^2] + 1/(k+1)^2
≤ (2 - 1/k) + 1/(k+1)^2, by inductive hypothesis
It suffices to show that
-1/k + 1/(k+1)^2 ≤ 1/(k+1) for all k > 0.
This is true
<==> -(k+1)^2 + k ≤ k(k+1), clearing fractions
<==> -(k+1)^2 ≤ k^2, which is clearly true for k > 0.
I hope this helps!