In a weak induction proof you are ultimately looking for a connection between P k and P k 1 to prove your proposition true. In this case you will prove the theorem for the case n 3 and also show that the case for n k implies the case for n k 1. Show it is true for the first one.
The principle of mathematical induction is used to prove that a given proposition formula equality inequality is true for all positive integer numbers greater than or equal to some integer N.
Step 2 Inductive step It proves that if the statement is true for the n th iteration or number n then it is also. N 3 2 n is divisible by 3. This is an example of a proof by math induction. It is what we assume when we prove a theorem by induction.