Greg Egan on Nostr: TIL that the function: f(x) = √[x (a-x)] + √[x (b-x)] has a maximum where x is ...
TIL that the function:
f(x) = √[x (a-x)] + √[x (b-x)]
has a maximum where x is half the harmonic mean of a and b:
x_m = a b / (a+b)
where its value is the geometric mean of a and b:
f(x_m) = √[a b]
But this doesn’t generalise if you add more terms, like √[x (c-x)]
Published at
2025-03-02 07:08:35 UTCEvent JSON
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"content": "TIL that the function:\n\nf(x) = √[x (a-x)] + √[x (b-x)]\n\nhas a maximum where x is half the harmonic mean of a and b:\n\nx_m = a b / (a+b)\n\nwhere its value is the geometric mean of a and b:\n\nf(x_m) = √[a b]\n\nBut this doesn’t generalise if you add more terms, like √[x (c-x)]",
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