Last week, @dmonniaux published an interesting post entitled l’erreur n’a rien d’original  on  his blog. He was asking the following question : let , and denote three real-valued coefficients, under which assumption on those three coefficients does has a real-valued root ?

Everyone aswered , but no one mentioned that it is necessary to have a proper quadratic equation, first. For instance, if both and are null, there are no roots.

Continue reading What happens if we forget a trivial assumption ? →