Q24 of 24 Page 4

(2n + 7) < (n+3)2.


Let P(n) = (2n + 7) < (n+3)2
P(1) is true
Let P(k) = (2k+7) < (k+3)2
To Prove P(k+1) = (2(k+1)+7) < (k + 4)2
                           
= [2k+9] < (k+4)2
                           
= [(k+3)2 – 9] < (k + 4)2
                           
= [( k+3+3) (k+3-3)] < ( k+4)2
                           
= [(k+6)(k) < (k+4)2
                           
= (k2 + 6k) < (k2 + 8k + 16)
The given expression is true for P(k+1)

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