Hyperbolic Functions¶
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class
sage.functions.hyperbolic.
Function_arccosh
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic cosine function.
EXAMPLES:
sage: arccosh(1/2) arccosh(1/2) sage: arccosh(1 + I*1.0) 1.06127506190504 + 0.904556894302381*I sage: float(arccosh(2)) 1.3169578969248168 sage: cosh(float(arccosh(2))) 2.0 sage: arccosh(complex(1, 2)) # abs tol 1e-15 (1.5285709194809982+1.1437177404024204j)
Warning
If the input is in the complex field or symbolic (which includes rational and integer input), the output will be complex. However, if the input is a real decimal, the output will be real or \(NaN\). See the examples for details.
sage: arccosh(0.5) NaN sage: arccosh(1/2) arccosh(1/2) sage: arccosh(1/2).n() NaN sage: arccosh(CC(0.5)) 1.04719755119660*I sage: arccosh(0) 1/2*I*pi sage: arccosh(-1) I*pi
To prevent automatic evaluation use the
hold
argument:sage: arccosh(-1,hold=True) arccosh(-1)
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: arccosh(-1,hold=True).simplify() I*pi
conjugate(arccosh(x))==arccosh(conjugate(x))
unless on the branch cut which runs along the real axis from +1 to -inf.:sage: conjugate(arccosh(x)) conjugate(arccosh(x)) sage: var('y', domain='positive') y sage: conjugate(arccosh(y)) conjugate(arccosh(y)) sage: conjugate(arccosh(y+I)) conjugate(arccosh(y + I)) sage: conjugate(arccosh(1/16)) conjugate(arccosh(1/16)) sage: conjugate(arccosh(2)) arccosh(2) sage: conjugate(arccosh(I/2)) arccosh(-1/2*I)
TESTS:
sage: arccosh(x).operator() arccosh sage: latex(arccosh(x)) {\rm arccosh}\left(x\right) sage: acosh(x)._sympy_() acosh(x)
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class
sage.functions.hyperbolic.
Function_arccoth
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic cotangent function.
EXAMPLES:
sage: arccoth(2.0) 0.549306144334055 sage: arccoth(2) arccoth(2) sage: arccoth(1 + I*1.0) 0.402359478108525 - 0.553574358897045*I sage: arccoth(2).n(200) 0.54930614433405484569762261846126285232374527891137472586735 sage: bool(diff(acoth(x), x) == diff(atanh(x), x)) True sage: diff(acoth(x), x) -1/(x^2 - 1)
Using first the \(.n(53)\) method is slightly more precise than converting directly to a
float
:sage: float(arccoth(2)) # abs tol 1e-16 0.5493061443340548 sage: float(arccoth(2).n(53)) # Correct result to 53 bits 0.5493061443340549 sage: float(arccoth(2).n(100)) # Compute 100 bits and then round to 53 0.5493061443340549
TESTS:
sage: latex(arccoth(x)) \operatorname{arccoth}\left(x\right) sage: acoth(x)._sympy_() acoth(x)
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class
sage.functions.hyperbolic.
Function_arccsch
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic cosecant function.
EXAMPLES:
sage: arccsch(2.0) 0.481211825059603 sage: arccsch(2) arccsch(2) sage: arccsch(1 + I*1.0) 0.530637530952518 - 0.452278447151191*I sage: arccsch(1).n(200) 0.88137358701954302523260932497979230902816032826163541075330 sage: float(arccsch(1)) 0.881373587019543 sage: diff(acsch(x), x) -1/(sqrt(x^2 + 1)*x) sage: latex(arccsch(x)) \operatorname{arccsch}\left(x\right)
TESTS:
Check if trac ticket #20818 is fixed:
sage: arccsch(float(0.1)) 2.99822295029797
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class
sage.functions.hyperbolic.
Function_arcsech
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic secant function.
EXAMPLES:
sage: arcsech(0.5) 1.31695789692482 sage: arcsech(1/2) arcsech(1/2) sage: arcsech(1 + I*1.0) 0.530637530952518 - 1.11851787964371*I sage: arcsech(1/2).n(200) 1.3169578969248167086250463473079684440269819714675164797685 sage: float(arcsech(1/2)) 1.3169578969248168 sage: diff(asech(x), x) -1/(sqrt(-x^2 + 1)*x) sage: latex(arcsech(x)) \operatorname{arcsech}\left(x\right) sage: asech(x)._sympy_() asech(x)
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class
sage.functions.hyperbolic.
Function_arcsinh
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic sine function.
EXAMPLES:
sage: arcsinh arcsinh sage: arcsinh(0.5) 0.481211825059603 sage: arcsinh(1/2) arcsinh(1/2) sage: arcsinh(1 + I*1.0) 1.06127506190504 + 0.666239432492515*I
To prevent automatic evaluation use the
hold
argument:sage: arcsinh(-2,hold=True) arcsinh(-2)
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: arcsinh(-2,hold=True).simplify() -arcsinh(2)
conjugate(arcsinh(x))==arcsinh(conjugate(x))
unless on the branch cuts which run along the imaginary axis outside the interval [-I, +I].:sage: conjugate(arcsinh(x)) conjugate(arcsinh(x)) sage: var('y', domain='positive') y sage: conjugate(arcsinh(y)) arcsinh(y) sage: conjugate(arcsinh(y+I)) conjugate(arcsinh(y + I)) sage: conjugate(arcsinh(1/16)) arcsinh(1/16) sage: conjugate(arcsinh(I/2)) arcsinh(-1/2*I) sage: conjugate(arcsinh(2*I)) conjugate(arcsinh(2*I))
TESTS:
sage: arcsinh(x).operator() arcsinh sage: latex(arcsinh(x)) {\rm arcsinh}\left(x\right) sage: asinh(x)._sympy_() asinh(x)
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class
sage.functions.hyperbolic.
Function_arctanh
¶ Bases:
sage.symbolic.function.GinacFunction
The inverse of the hyperbolic tangent function.
EXAMPLES:
sage: arctanh(0.5) 0.549306144334055 sage: arctanh(1/2) arctanh(1/2) sage: arctanh(1 + I*1.0) 0.402359478108525 + 1.01722196789785*I
To prevent automatic evaluation use the
hold
argument:sage: arctanh(-1/2,hold=True) arctanh(-1/2)
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: arctanh(-1/2,hold=True).simplify() -arctanh(1/2)
conjugate(arctanh(x))==arctanh(conjugate(x))
unless on the branch cuts which run along the real axis outside the interval [-1, +1].:sage: conjugate(arctanh(x)) conjugate(arctanh(x)) sage: var('y', domain='positive') y sage: conjugate(arctanh(y)) conjugate(arctanh(y)) sage: conjugate(arctanh(y+I)) conjugate(arctanh(y + I)) sage: conjugate(arctanh(1/16)) arctanh(1/16) sage: conjugate(arctanh(I/2)) arctanh(-1/2*I) sage: conjugate(arctanh(-2*I)) arctanh(2*I)
TESTS:
sage: arctanh(x).operator() arctanh sage: latex(arctanh(x)) {\rm arctanh}\left(x\right) sage: atanh(x)._sympy_() atanh(x)
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class
sage.functions.hyperbolic.
Function_cosh
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic cosine function.
EXAMPLES:
sage: cosh(pi) cosh(pi) sage: cosh(3.1415) 11.5908832931176 sage: float(cosh(pi)) 11.591953275521519 sage: RR(cosh(1/2)) 1.12762596520638 sage: latex(cosh(x)) \cosh\left(x\right) sage: cosh(x)._sympy_() cosh(x)
To prevent automatic evaluation, use the
hold
parameter:sage: cosh(arcsinh(x),hold=True) cosh(arcsinh(x))
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: cosh(arcsinh(x),hold=True).simplify() sqrt(x^2 + 1)
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class
sage.functions.hyperbolic.
Function_coth
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic cotangent function.
EXAMPLES:
sage: coth(pi) coth(pi) sage: coth(0) Infinity sage: coth(pi*I) Infinity sage: coth(pi*I/2) 0 sage: coth(7*pi*I/2) 0 sage: coth(8*pi*I/2) Infinity sage: coth(7.*pi*I/2) -I*cot(3.50000000000000*pi) sage: coth(3.1415) 1.00374256795520 sage: float(coth(pi)) 1.0037418731973213 sage: RR(coth(pi)) 1.00374187319732 sage: coth(complex(1, 2)) # abs tol 1e-15 (0.8213297974938518+0.17138361290918508j) sage: bool(diff(coth(x), x) == diff(1/tanh(x), x)) True sage: diff(coth(x), x) -1/sinh(x)^2 sage: latex(coth(x)) \operatorname{coth}\left(x\right) sage: coth(x)._sympy_() coth(x)
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class
sage.functions.hyperbolic.
Function_csch
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic cosecant function.
EXAMPLES:
sage: csch(pi) csch(pi) sage: csch(3.1415) 0.0865975907592133 sage: float(csch(pi)) 0.0865895375300469... sage: RR(csch(pi)) 0.0865895375300470 sage: csch(0) Infinity sage: csch(pi*I) Infinity sage: csch(pi*I/2) -I sage: csch(7*pi*I/2) I sage: csch(7.*pi*I/2) -I*csc(3.50000000000000*pi) sage: bool(diff(csch(x), x) == diff(1/sinh(x), x)) True sage: diff(csch(x), x) -coth(x)*csch(x) sage: latex(csch(x)) {\rm csch}\left(x\right) sage: csch(x)._sympy_() csch(x)
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class
sage.functions.hyperbolic.
Function_sech
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic secant function.
EXAMPLES:
sage: sech(pi) sech(pi) sage: sech(3.1415) 0.0862747018248192 sage: float(sech(pi)) 0.0862667383340544... sage: RR(sech(pi)) 0.0862667383340544 sage: sech(0) 1 sage: sech(pi*I) -1 sage: sech(pi*I/2) Infinity sage: sech(7*pi*I/2) Infinity sage: sech(8*pi*I/2) 1 sage: sech(8.*pi*I/2) sec(4.00000000000000*pi) sage: bool(diff(sech(x), x) == diff(1/cosh(x), x)) True sage: diff(sech(x), x) -sech(x)*tanh(x) sage: latex(sech(x)) \operatorname{sech}\left(x\right) sage: sech(x)._sympy_() sech(x)
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class
sage.functions.hyperbolic.
Function_sinh
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic sine function.
EXAMPLES:
sage: sinh(pi) sinh(pi) sage: sinh(3.1415) 11.5476653707437 sage: float(sinh(pi)) 11.54873935725774... sage: RR(sinh(pi)) 11.5487393572577 sage: latex(sinh(x)) \sinh\left(x\right) sage: sinh(x)._sympy_() sinh(x)
To prevent automatic evaluation, use the
hold
parameter:sage: sinh(arccosh(x),hold=True) sinh(arccosh(x))
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: sinh(arccosh(x),hold=True).simplify() sqrt(x + 1)*sqrt(x - 1)
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class
sage.functions.hyperbolic.
Function_tanh
¶ Bases:
sage.symbolic.function.GinacFunction
The hyperbolic tangent function.
EXAMPLES:
sage: tanh(pi) tanh(pi) sage: tanh(3.1415) 0.996271386633702 sage: float(tanh(pi)) 0.99627207622075 sage: tan(3.1415/4) 0.999953674278156 sage: tanh(pi/4) tanh(1/4*pi) sage: RR(tanh(1/2)) 0.462117157260010
sage: CC(tanh(pi + I*e)) 0.997524731976164 - 0.00279068768100315*I sage: ComplexField(100)(tanh(pi + I*e)) 0.99752473197616361034204366446 - 0.0027906876810031453884245163923*I sage: CDF(tanh(pi + I*e)) # rel tol 2e-15 0.9975247319761636 - 0.002790687681003147*I
To prevent automatic evaluation, use the
hold
parameter:sage: tanh(arcsinh(x),hold=True) tanh(arcsinh(x))
To then evaluate again, we currently must use Maxima via
sage.symbolic.expression.Expression.simplify()
:sage: tanh(arcsinh(x),hold=True).simplify() x/sqrt(x^2 + 1)
TESTS:
sage: latex(tanh(x)) \tanh\left(x\right) sage: tanh(x)._sympy_() tanh(x)
Check that real/imaginary parts are correct (trac ticket #20098):
sage: tanh(1+2*I).n() 1.16673625724092 - 0.243458201185725*I sage: tanh(1+2*I).real().n() 1.16673625724092 sage: tanh(1+2*I).imag().n() -0.243458201185725 sage: tanh(x).real() sinh(2*real_part(x))/(cos(2*imag_part(x)) + cosh(2*real_part(x))) sage: tanh(x).imag() sin(2*imag_part(x))/(cos(2*imag_part(x)) + cosh(2*real_part(x)))
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class
sage.functions.hyperbolic.
HyperbolicFunction
(name, latex_name=None, conversions=None, evalf_float=None)¶ Bases:
sage.symbolic.function.BuiltinFunction
Abstract base class for the functions defined in this file.
EXAMPLES:
sage: from sage.functions.hyperbolic import HyperbolicFunction sage: f = HyperbolicFunction('foo', latex_name='\\foo', conversions={'mathematica':'Foo'},evalf_float=lambda x: 2*x) sage: f(x) foo(x) sage: f(0.5r) 1.0 sage: latex(f(x)) \foo\left(x\right) sage: f(x)._mathematica_init_() 'Foo[x]'