# Why do some respondents avoid the simple answer?

I posed my first Math Stack question, earlier this evening. It was on the product of expectation values. I received an answer that enabled me to solve my problem by using Cauchy's Inequality. The respondent referred to Jensen's Inequality, a more comprehensive relationship than Cauchy's as I found from reading a Wikipedia article. To understand the Wiki article, I should have far more mathematical background than I do: measure theory, for example. Why not urge respondents to gauge the level of their replies to the level of the questioner? I am sure that my statement makes clear that I am not an advanced graduate student in mathematics. If I were, I would not have needed to pose the question in the first place.

• Although Jensen's Inequality is applicable in more general measure theoretic settings, it can be stated simply as $$\int_Eg(x)\,\mathrm{d}x =1\implies\int_E\phi(f(x))g(x)\,\mathrm{d}x \ge\phi\left(\int_Ef(x)g(x)\,\mathrm{d}x\right)$$ for $g(x)\ge0$ and any convex function $\phi$ whose domain includes an interval containing the range of $f$. Don't be overwhelmed by Wikipedia's generality, which is useful in more advanced situations; Jensen's Inequality is useful in less advanced settings, too. – robjohn May 11 '15 at 3:08
• I must admit I find this question partly disingenuous. When the answer was posted to your question, you gave no context as to your background or what sorts of answers you were hoping for. The answerer gave a very natural answer that has the added benefit of being short enough to fit on a napkin. Afterwards, you edited your question and asked for Cauchy's Inequality. This seems like a good example of why it's good to clarify questions, give context, and what you've tried. – davidlowryduda May 11 '15 at 3:14
• You asked the question, goedelite, but you may not be the only one to read the answer. Someone else might benefit from an answer that you don't understand. You might even benefit from it yourself, some day when you've learned more stuff. You don't have to praise the answer, but it's a bit small-minded to denounce it. – Gerry Myerson May 11 '15 at 3:19