// Minimax polynomial approximations
DATA coshe2<>+0(SB)/8, $0.500000000000004237e+00
GLOBL coshe2<>+0(SB), RODATA, $8
DATA coshe3<>+0(SB)/8, $0.166666666630345592e+00
GLOBL coshe3<>+0(SB), RODATA, $8
DATA coshe4<>+0(SB)/8, $0.416666664838056960e-01
GLOBL coshe4<>+0(SB), RODATA, $8
DATA coshe5<>+0(SB)/8, $0.833349307718286047e-02
GLOBL coshe5<>+0(SB), RODATA, $8
DATA coshe6<>+0(SB)/8, $0.138926439368309441e-02

	}

	if sign {
		temp = -temp
	}
	return temp
}

// Cosh returns the hyperbolic cosine of x.
//
// Special cases are:
//
//	Cosh(±0) = 1
//	Cosh(±Inf) = +Inf
//	Cosh(NaN) = NaN
func Cosh(x float64) float64 {
	if haveArchCosh {
		return archCosh(x)
	}
	return cosh(x)
}

func cosh(x float64) float64 {
	x = Abs(x)
	if x > 21 {
		return Exp(x) * 0.5
	}
	ex := Exp(x)

// Complex hyperbolic cosine
//
// DESCRIPTION:
//
// ccosh(z) = cosh x  cos y + i sinh x sin y .
//
// ACCURACY:
//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    IEEE      -10,+10     30000       2.9e-16     8.1e-17

// Cosh returns the hyperbolic cosine of x.
func Cosh(x complex128) complex128 {
	switch re, im := real(x), imag(x); {

	case re == 0 && math.IsNaN(im):
		return x
	}
	d := math.Cos(2*real(x)) + math.Cosh(2*imag(x))
	if math.Abs(d) < 0.25 {
		d = tanSeries(x)
	}
	if d == 0 {
		return Inf()
	}
	return complex(math.Sin(2*real(x))/d, math.Sinh(2*imag(x))/d)
}

// Complex hyperbolic tangent
//
// DESCRIPTION:
//
// tanh z = (sinh 2x  +  i sin 2y) / (cosh 2x + cos 2y) .
//
// ACCURACY:
//
//                      Relative error:

// license that can be found in the LICENSE file.

package math

// Export internal functions and variable for testing.
var Log10NoVec = log10
var CosNoVec = cos
var CoshNoVec = cosh
var SinNoVec = sin
var SinhNoVec = sinh
var TanhNoVec = tanh
var Log1pNovec = log1p
var AtanhNovec = atanh
var AcosNovec = acos
var AcoshNovec = acosh
var AsinNovec = asin
var AsinhNovec = asinh

//      MINLOG = -8.872283911167299960540e+01 = log(2**-128)
//
// A rational function is used for |x| < 0.625.  The form
// x + x**3 P(x)/Q(x) of Cody & Waite is employed.
// Otherwise,
//      tanh(x) = sinh(x)/cosh(x) = 1  -  2/(exp(2x) + 1).
//
// ACCURACY:
//
//                      Relative error:
// arithmetic   domain     # trials      peak         rms
//    IEEE      -2,2        30000       2.5e-16     5.8e-17
//

	fmt.Printf("%.2f", math.Copysign(3.2, -1))
	// Output: -3.20
}

func ExampleCos() {
	fmt.Printf("%.2f", math.Cos(math.Pi/2))
	// Output: 0.00
}

func ExampleCosh() {
	fmt.Printf("%.2f", math.Cosh(0))
	// Output: 1.00
}

func ExampleSin() {
	fmt.Printf("%.2f", math.Sin(math.Pi))
	// Output: 0.00
}

func ExampleSincos() {
	sin, cos := math.Sincos(0)
	fmt.Printf("%.2f, %.2f", sin, cos)