I've recently come across a http://technologyinterface.nmsu.edu/Spring08/" [Broken] for why power is maximised in a component when its resistance [tex]R_L[/tex] equals the internal resistance [tex]R[/tex].(adsbygoogle = window.adsbygoogle || []).push({});

But in part (5) of method 1, we need to find the minimum non-negative value that the expression [tex]k+k^-^1[/tex] can take. For this they use the inequality [tex](k-1)^2 \geq 0[/tex] and then expand it to [tex]k^2-2k+1 \geq 0 [/tex] which is then in turn divided by [tex]k [/tex] and rearranged to get [tex]k+k^-^1 \geq 2[/tex]

The problem I have grasping is the part where they come up with the inequality to solve this problem. This is a step I have never come across, and I was wondering if this method had a name.

Thanks

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# Finding the minimum value that an expression can take.

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