Second ou troisième degré ?

It cannot be overemphasized, however, how crucially success depends on having a good first guess for the solution, especially for multidimensional problems. This crucial beginning usually depends on analysis rather than numerics. Carefully crafted initial estimates rewards you not only with reduced computational effort, but also with understanding and increased self-esteem.

in Numerical Recipes in C, ch. 9, p. 348.

Hum... je suis perplexe.