How to find an argument of $ z=1-\cos\varphi-i\sin\varphi $?
107067
Finding the argument of $z=1-\cos(2\theta)-i\sin(2\theta)$
57750
Solve identity: $\frac {\sin x}{1-\cos x} = \frac {1+\cos x}{\sin x}$
6465
How to prove periodicity of $\sin(x)$ or $\cos(x)$ starting from the Taylor series expansion?
123476
Prove $[\sin x]' = \cos x$ without using $\lim\limits_{x\to 0}\frac{\sin x}{x} = 1$
20047
At $z=0$ the function $f(z)=\exp({z\over 1-\cos z})$ has
33396
Generalizing a Trig Identity
76490
Proving that $\cos(\arcsin(x))=\sqrt{1-x^2}$
61119
Evaluate $\prod_{i=1}^{89} \sin (i)$
39492
Finding $z\in \mathbb C$ with $\sin z = 2$?
29604
How to solve $\sin x +\cos x = 1$?
24128
How do i show that $w=z^2$ maps $|z-1|\leq 1$ onto $R=2(1+\cos \theta)$?
118577
Fallacious proof involving trigonometry
66793
Is there a fast technique to tell that the poles of $\frac{1}{\sin z}$ are simple?
1210
Write an expression for $(\cos θ + i\sin θ)^4$ using De Moivre’s Theorem.
154216
Solve $\sin(z) = z$ in complex numbers
102320
Is my solution correct for solving $\cos(z)=2$, $z\in \mathbb{C}$
101448
Is $\sin^2(z) + \cos^2(z)=1$ still true for $z \in \Bbb{C}$?