Step 1: Understanding the Problem
The problem asks us to use mathematical induction to find the target inequality when n=k+1, given that the inequality holds when n=k.
Step 2: Applying Mathematical Induction
Assume that the inequality holds when n=k, i.e., 221+dfrac132+ldots+dfrac1(k+1)2>dfrac12−dfrac1k+2.
When n=k+1, the left side of the inequality becomes 221+dfrac132+ldots+dfrac1(k+1)2+(k+2)21.
Step 3: Simplifying the Inequality
According to our assumption, we know that 221+dfrac132+ldots+dfrac1(k+1)2>dfrac12−dfrac1k+2.
Adding (k+2)21 to both sides of the inequality gives us 221+dfrac132+ldots+dfrac1(k+1)2+(k+2)21>dfrac12−dfrac1k+2+(k+2)21.
Step 4: Final Inequality
Therefore, when n=k+1, the target inequality to be proved is 221+dfrac132+ldots+dfrac1(k+1)2+(k+2)21>dfrac12−dfrac1k+2+(k+2)21.