proofs on trigonometric identities involving complex numbers
30600
Why does $\tan^{-1}(1)+\tan^{-1}(2)+\tan^{-1}(3)=\pi$?
13297
Prove the following trigonometric identity without a calculator involved
127759
Prove that $\frac{\sin(a)}{\sin(b)} < \frac{a}{b} < \frac{\tan(a)}{\tan(b)}$ where $0 < b < a < \frac{\pi}{2}$
46701
Complex Number Proof Questions
90933
Finding the roots of complex numbers
71413
Proving complex series $1 + \cos\theta + \cos2\theta +... + \cos n\theta $
46353
Proof that $\cos(\pi/3)=1/2$
140968
Proof for Property of Complex Numbers
7296
Prove $(1-\cos x)/\sin x = \tan x/2$
146047
Proving that $\cos(2\pi/n)$ is algebraic
35244
Prove $\sin^2\theta + \cos^2\theta = 1$
119628
Proving an identity relating to the complex modulus: $z\bar{a}+\bar{z}a \leq 2|a||z|$
139625
Proof of a Fibonacci identity
137844
Proof of $\sin nx=2^{n-1}\prod_{k=0}^{n-1} \sin\left( x + \frac{k\pi}{n} \right)$
147886
Proof of the angle sum identity for $\sin$
54175
Prove the trigonometric identity $\sin^4{x} = \frac{3-4\cos{2x}+\cos{4x}}{8}$
122169
Prove $\sin(\pi/2)=1$ using Taylor series