Chapter 11.4, Problem 41E

Some statements are false for the first few positive integers, but trite for sonic positive integer in on. In these instances, you can prove $S_n$ for $n\ge m$ by showing that $S_m$ is true and that $S_k$ implies $S_k$ when $k\ge m$. Use this extended principle of mathematical induction to prove that each statement in Exercises 4l-d2 is true.

Prove that $n^2>2n+1$ for $n\ge 3$, Show that die formula is true for $n=3$ and then use step 2 of mathematical induction.