First, observe that $ f(u) < u $ for all $ u > 0 $, since $ \frac{u^4}{4} > 0 $. Thus, the sequence $ b_n $ is strictly decreasing and bounded below by 0. Therefore, it converges to some limit $ L \geq 0 $.

Wed, 06 May 2026 14:21:56 +0000

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