Prove that $\sin x0$
53307
how to strictly prove $\sin x<x$ for $0<x<\frac{\pi}{2}$
33628
Prove that $\sin(\sqrt x)$ not periodic
141787
Anybody know a proof of $\prod_{n=1}^\infty\cos(x/2^n)=\sin x/x$.
23288
Prove that $x^2<\sin x \tan x$ as $x \to 0$
91000
Prove that $\frac{1}{a+1}0$
84730
use the fact that $\tan 2x=\sin2x \ /\cos2x$ to prove that $\tan 2x=2\tan x/(1-\tan^2x)$
42545
If $ a,b,c\in \left(0,\frac{\pi}{2}\right)\;,$ Then prove that $\frac{\sin (a+b+c)}{\sin a+\sin b+\sin c}<1$
54512
How do I prove: $\cos (\theta + 90^\circ) \equiv - \sin \theta $
60559
How prove this $x^3<\sin^2{x}\tan{x},x\in\left(0,\dfrac{\pi}{2}\right)$
48586
Prove: $\cot x=\sin x\,\sin\left(\frac{\pi}{2}-x\right)+\cos^2x\,\cot x$
114411
Simple Proof of the Euler Identity $\exp{i\theta}=\cos{\theta}+i\sin{\theta}$
123920
How prove this inequality $\tan{(\sin{x})}>\sin{(\tan{x})}$
124208
Proof $|\sin(x) - x| \le \frac{1}{3.2}|x|^3$
9986
Prove $ \sin(A+B)\sin(A-B)=\sin^2A-\sin^2B $
13804
Prove the set of which sin(nx) converges has Lebesgue measure zero (from Baby Rudin Chapter 11)
53984
Prove by induction: $\sum\limits_{k=1}^{n}sin(kx)=\frac{sin(\frac{n+1}{2}x)sin\frac{nx}{2}}{sin\frac{x}{2}}$
105487
Prove that $\sin x \cdot \sin (2x) \cdot \sin(3x) < \tfrac{9}{16}$ for all $x$