For any number n, if n2 is even, then n must be even. This means n being even is a <u>Necessary condition </u>for n2 being even.
Step-by-step explanation:
<u>Necessary Condition:</u>-A condition that says that the result has to be true but does not guarantee any kind of result.
Suppose we assume that n is not even (i.e., it is odd)
and show that n^2 is not even (i.e., it is odd).
n is odd then you can write
n = 2*k + 1 for an integer k.
Then,
n^2 = 4*k^2 + 4*k + 1
= 2 * (2*k^2 + 2*k) + 1
which is clearly odd.
<u>This completes the proof that for any number n, if n2 is even, then n must be even</u>