A sequence is defined by `a_n=n^3-6n^2+11 n-6.` Show that the first three terms of the sequence are zero and all other terms are positive.

Explanation

Given that :


`a_{n}=n^{3}-6 n^{2}+11 n-6`


Putting `n=1,2,3`


`a_{1}=1^{3}-6(1)^{2}+11(1)-6=12-12=0 `


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