$\tan \frac{x}{2}>\frac{x}{2}$ for all $x \in (0, \pi)$
88989
Why $x<\tan{x}$ while $0<x<\frac{\pi}{2}$?
17925
Vardi's Integral: $\int_{\pi/4}^{\pi/2} \ln (\ln(\tan x))dx $
23288
Prove that $x^2<\sin x \tan x$ as $x \to 0$
11059
Verify the identity: $\tan^{-1} x +\tan^{-1} (1/x) = \pi /2$
77002
$\int_{0}^{\frac{\pi}{2}}\frac{d\theta}{a + \sin^2(\theta)} = \frac{\pi}{2\sqrt{a(a+1)}}$, for $a > 0$
106828
If $0 \lt x \lt \frac{\pi}{2}$, is $\cos(x) \le \frac{\sin(x)}{x} \le \frac{1}{\cos(x)}$?
104272
Inequality of $\vert \text{tanh}(x)-x+\frac{x^3}{3}\vert\leq\frac{1}{8}$ for $x\in[-1/4,1/4]$
17769
Show that $\frac{\sin x}{\cos 3x}+\frac{\sin 3x}{\cos 9x}+\frac{\sin 9x}{\cos 27x} = \frac{1}{2}\left(\tan 27x-\tan x\right)$
31063
Evaluating $\int_0^2(\tan^{-1}(\pi x)-\tan^{-1} x)\,\mathrm{d}x$
156881
How prove this inequality $I=\int_{0}^{\sqrt{2\pi}}\sin{x^2}dx>0$
106803
How to see $\cos x \leq \exp(-x^2/2)$ on $x \in [0,\pi/2]$?
118884
The sine inequality $\frac2\pi x \le \sin x \le x$ for $0<x<\frac\pi2$
47206
$-1 = 0$ by integration by parts of $\tan(x)$
51979
Is there a geometrical method to prove $x<\frac{\sin x +\tan x}{2}$?
85872
Prove $1 + \tan^2\theta = \sec^2\theta$
53307
how to strictly prove $\sin x<x$ for $0<x<\frac{\pi}{2}$
11387
Mean Value Theorem: $\frac{2}{\pi}<\frac{\sin x}{x}<1$