```
cosh(x)
sinh(x)
tanh(x)
acosh(x)
asinh(x)
atanh(x)
```

x

a numeric or complex vector

`Math`

group generic.`Math`

group generic. Branch cuts are consistent with the inverse trigonometric functions
`asin`

*et seq*, and agree with those defined in Abramowitz
and Stegun, figure 4.7, page 86. The behaviour actually on the cuts
follows the C99 standard which requires continuity coming round the
endpoint in a counter-clockwise direction.

`cos`

, `sin`

,
`tan`

, and their inverses
`acos`

, `asin`

, `atan`

. The logistic distribution function `plogis`

is a shifted
version of `tanh()`

for numeric `x`

.