I'm having trouble proving this by induction. We need to show that $P(k+1)$ is true: $$\sum_{i=2}^{k+1} \frac{1}{i^2}\leq 1.$$
Don't know where to go from here. Any help?
I'm having trouble proving this by induction. We need to show that $P(k+1)$ is true: $$\sum_{i=2}^{k+1} \frac{1}{i^2}\leq 1.$$
Don't know where to go from here. Any help?
Hint. Try to apply induction to $$ \sum_{k=2}^n \frac1{k^2}\le 1-\frac1{n},\qquad n\ge2. $$