Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 169474

for questions involving inequalities, upper and lower bounds.

2 votes
Accepted

Positive, monotone decreasing function, with derivative limit in 0 equal to ∞ submultiplicat...

Define $f$ on $]0,e^{-2}]$ by $$f(x) = \frac{1}{-\sqrt{x}\ln(x)}.$$ Then $f$ is positive, decreasing since $$\frac{\mathrm{d}}{\mathrm{d}x}\big(-\sqrt{x}\ln(x)\big) = \frac{-\ln(x)-2}{2\sqrt{x}} \ge 0 …
Christophe Leuridan's user avatar
12 votes

Trigonometric inequality

I give a way that may work for odd numbers. This is too long for a comment. First, the quantity $$\cos\Big(\frac{2m\pi}{p}\Big)+\cos\Big(\frac{2n\pi}{q}\Big) = 2\cos\Big(\pi\Big(\frac{m}{p}+\frac{n}{ …
Christophe Leuridan's user avatar
1 vote
Accepted

Equality cases in a certain case of Jensen's inequality

Since the distribution of the r.v. $X$ is zero-mean, $X$ integrable (hence also the copy $Y$). The equality is attained iff the distribution of $X$ is carried by at most two points. Indeed, by indepen …
Christophe Leuridan's user avatar