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package math32
func Sinh(x float32) float32 {
// The coefficients are #2029 from Hart & Cheney. (20.36D)
const (
P0 = -0.6307673640497716991184787251e+6
P1 = -0.8991272022039509355398013511e+5
P2 = -0.2894211355989563807284660366e+4
P3 = -0.2630563213397497062819489e+2
Q0 = -0.6307673640497716991212077277e+6
Q1 = 0.1521517378790019070696485176e+5
Q2 = -0.173678953558233699533450911e+3
)
sign := false
if x < 0 {
x = -x
sign = true
}
var temp float32
switch {
case x > 21:
temp = Exp(x) * 0.5
case x > 0.5:
ex := Exp(x)
temp = (ex - 1/ex) * 0.5
default:
sq := x * x
temp = (((P3*sq+P2)*sq+P1)*sq + P0) * x
temp = temp / (((sq+Q2)*sq+Q1)*sq + Q0)
}
if sign {
temp = -temp
}
return temp
}
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