What is the relation to $\sinh{x},\cosh{x}$ and $\sin{x},\cos{x}$
67172
What's the intuition behind the identities $\cos(z)= \cosh(iz)$ and $\sin(z)=-i\sinh(iz)$?
128795
$n$th derivative of $e^x \sin x$
107248
Prove that the set $ \{\sin(x),\cos(x),\sin(2x),\cos(2x)\}$ is linearly independent.
11509
Relationship between $\operatorname{ord}(ab), \operatorname{ord}(a)$, and $\operatorname{ord}(b)$
116270
Functional equations leading to sine and cosine
141273
When is $\sin(x)$ rational?
101448
Is $\sin^2(z) + \cos^2(z)=1$ still true for $z \in \Bbb{C}$?
139113
Does the series $\sum \sin^{(n)}(1)$ converge, where $\sin^{(n)}$ denotes the $n$-fold composition of $\sin$?
40235
How would I differentiate $\sin{x}^{\cos{x}}?$
118715
Inverse Laplace transform of $\frac{1}{s\sinh{c\sqrt{s}}}$
66852
Integral $ \int_{-\infty}^{\infty}\frac{x^{2}}{\cosh\left(x\right)}\,{\rm d}x $
52305
Is there a general relation between $a/b$ and $(a+c)/(b+c)$ where $a,b,c > 0 $?
80680
General term of Taylor Series of $\sin x$ centered at $\pi/4$
6549
What is the integral of $\sin(\cos x)$?
8711
Problems in the relation $a=v\frac{\mathrm{d}v}{\mathrm{d}x}$
108223
If $\cos x=\cos y$ and $\sin x=\sin y$ is $x=y$ or $x=2\pi,y=0$ or $x=0,y=2\pi$? $x,y\in[0,2\pi]$
94283
Different ways finding the derivative of $\sin$ and $\cos$.