# ctanhf, ctanh, ctanhl

< c‎ | numeric‎ | complex

C
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Complex number arithmetic
Types and the imaginary constant
Manipulation
Power and exponential functions
Trigonometric functions
Hyperbolic functions
 ccosh csinh ctanh

 Defined in header `` float complex       ctanhf( float complex z ); (1) (since C99) double complex      ctanh( double complex z ); (2) (since C99) long double complex ctanhl( long double complex z ); (3) (since C99) Defined in header `` #define tanh( z ) (4) (since C99)
1-3) Computes the complex hyperbolic tangent of `z`.
4) Type-generic macro: If `z` has type long double complex, `ctanhl` is called. if `z` has type double complex, `ctanh` is called, if `z` has type float complex, `ctanhf` is called. If `z` is real or integer, then the macro invokes the corresponding real function (tanhf, tanh, tanhl). If `z` is imaginary, then the macro invokes the corresponding real version of the function tan, implementing the formula tanh(iy) = i tan(y), and the return type is imaginary.

### Parameters

 z - complex argument

### Return value

If no errors occur, complex hyperbolic tangent of `z` is returned

### Error handling and special values

Errors are reported consistent with math_errhandling

If the implementation supports IEEE floating-point arithmetic,

• ctanh(conj(z)) == conj(ctanh(z))
• ctanh(-z) == -ctanh(z)
• If `z` is `+0+0i`, the result is `+0+0i`
• If `z` is `x+∞i` (for any finite x), the result is `NaN+NaNi` and FE_INVALID is raised
• If `z` is `x+NaN` (for any finite x), the result is `NaN+NaNi` and FE_INVALID may be raised
• If `z` is `+∞+yi` (for any finite positive y), the result is `1+0i`
• If `z` is `+∞+∞i`, the result is `1±0i` (the sign of the imaginary part is unspecified)
• If `z` is `+∞+NaNi`, the result is `1±0i` (the sign of the imaginary part is unspecified)
• If `z` is `NaN+0i`, the result is `NaN+0i`
• If `z` is `NaN+yi` (for any non-zero y), the result is `NaN+NaNi` and FE_INVALID may be raised
• If `z` is `NaN+NaNi`, the result is `NaN+NaNi`
1. per DR471, this only holds for non-zero x. If `z` is `0+∞i`, the result should be `0+NaNi`
2. per DR471, this only holds for non-zero x. If `z` is `0+NaNi`, the result should be `0+NaNi`