Came across this problem that ties together the Inequalities and Proofs topics really well. It’s a solid practice question for anyone looking to polish their calculus/proofs before trials.
It guides you through the whole derivation chain:

It guides you through the whole derivation chain:
- Part (i) & (ii): Using calculus (minimisation) to derive Young's Inequality.
- Part (iii): The classic induction proof for AM-GM.
- Part (iv): A satisfying application involving a cyclic sum.
