query: Proving a trigonometric identity:
positive_passages.docid: 17168
positive_passages.text: Find the value of $\sin\frac{2\pi}{7}+\sin\frac{4\pi}{7}+\sin\frac{8\pi}{7}$
negative_passages.docid: 44119
negative_passages.text: Prove that $\cos (A + B)\cos (A - B) = {\cos ^2}A - {\sin ^2}B$
negative_passages.docid: 138847
negative_passages.text: Tricky trigonometric sum evaluation
negative_passages.docid: 17769
negative_passages.text: Show that $\frac{\sin x}{\cos 3x}+\frac{\sin 3x}{\cos 9x}+\frac{\sin 9x}{\cos 27x} = \frac{1}{2}\left(\tan 27x-\tan x\right)$
negative_passages.docid: 50777
negative_passages.text: Prove that $4\sin\frac{2\pi}{7}- \tan\frac{\pi}{7}= \sqrt{7}$ .
negative_passages.docid: 85944
negative_passages.text: Prove $ \sin x + \frac{ \sin3x }{3} + ... + \frac{ \sin((2n-1)x) }{2n-1} >0 $
negative_passages.docid: 55869
negative_passages.text: Use the Maclaurin series to prove that $e^{i\theta} = cos(\theta) + isin(\theta)$
negative_passages.docid: 21941
negative_passages.text: Proving: $x = a_0 + \sum_{n=1}^{\infty}(a_n \cos nx + b_n \sin nx)$
negative_passages.docid: 65698
negative_passages.text: Proving $\sum\limits_{k=0}^{n}\cos(kx)=\frac{1}{2}+\frac{\sin(\frac{2n+1}{2}x)}{2\sin(x/2)}$
negative_passages.docid: 84730
negative_passages.text: use the fact that $\tan 2x=\sin2x \ /\cos2x$ to prove that $\tan 2x=2\tan x/(1-\tan^2x)$
negative_passages.docid: 71413
negative_passages.text: Proving complex series $1 + \cos\theta + \cos2\theta +... + \cos n\theta $
negative_passages.docid: 60559
negative_passages.text: How prove this $x^3<\sin^2{x}\tan{x},x\in\left(0,\dfrac{\pi}{2}\right)$
negative_passages.docid: 54512
negative_passages.text: How do I prove: $\cos (\theta + 90^\circ) \equiv - \sin \theta $
negative_passages.docid: 48394
negative_passages.text: Proving bessel identity $[J_0(x)]^2 + 2[J_1(x)]^2 + 2[J_2(x)]^2 + \cdots = 1$ and $|J_0(x)|\le 1$
negative_passages.docid: 135895
negative_passages.text: Proving the bounds of cosine
negative_passages.docid: 45725
negative_passages.text: Derivation of an identity with beta function.
negative_passages.docid: 142835
negative_passages.text: Proving :$\arctan(1)+\arctan(2)+ \arctan(3)=\pi$