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Prove that 1^2+2^2+dotdotdot+n^2>(n^2)/3...

Prove that `1^2+2^2+dotdotdot+n^2>(n^2)/3,``n in N`

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Given,
`1^2+2^2+3^2+......+n^2=(n(n+1)(2n+1))/6​`
If we put n=1 , we get,
`(1(1+1)(2+1)​)/6>(1^2)/3`​ so,`1>1/3`
Thus,`1^2+2^2+3^2+......+n^2>(n^2​)/3`
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