Mohammad Descartes


Posts : 100 Join date : 2009-11-05 Age : 35 Location : Right behind you
 | Subject: Proposed by Vincentiu Radulescu, University of Craiova, Romania Tue Feb 23, 2010 4:16 pm | |
| Prove that there does not exist a positive, twice differentiable function f:[0,\infty)\to R such that f(x)f"(x)+1\leq 0 for all x\geq 0.  |
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