Prove Even Integer for Natural Number n: Induction

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The discussion focuses on proving that (n^3 + 5n)/3 is an even integer for all natural numbers n using mathematical induction. The initial step involves substituting n+1 into the expression, leading to the equation (n^3 + 5n) + 3n(n+1) + 6. By dividing each term by 3, it becomes clear that the result remains an even integer. The conversation indicates that the user is comfortable with induction and finds the provided steps sufficient for understanding the proof. The proof effectively demonstrates the evenness of the expression for all natural numbers n.
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Use mathematical induction, to prove that \frac{n^{3}+5n}{3}


is an even integer for each natural number n.

I am fimilar with proof by induction but in most of the question that I have done have a
LHS = RHS which seems to simplifiy things a little bit.
Any help would be appreciated
Cheers
 
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asset101 said:
Use mathematical induction, to prove that \frac{n^{3}+5n}{3}
is an even integer for each natural number n.

I am fimilar with proof by induction...

Put n+1 in place of n.

(n+1)^3 + 5(n+1) = n^3+3n^2+3n+1+5n+5 = (n^3+5n) + 3n(n+1) + 6.

Now divide each term by 3 and see what kind of number you get.

Since you are familiar with induction, this should be enough.
 
Got it thanks mate
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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