Python sympy.coth函数代码示例

def test_coth_rewrite():
    x = Symbol('x')
    assert coth(x).rewrite(exp) == (exp(x) + exp(-x))/(exp(x) - exp(-x)) \
        == coth(x).rewrite('tractable')
    assert coth(x).rewrite(sinh) == -I*sinh(I*pi/2 - x)/sinh(x)
    assert coth(x).rewrite(cosh) == -I*cosh(x)/cosh(I*pi/2 - x)
    assert coth(x).rewrite(tanh) == 1/tanh(x)

def test_hyper_as_trig():
    from sympy.simplify.fu import _osborne as o, _osbornei as i, TR12

    eq = sinh(x)**2 + cosh(x)**2
    t, f = hyper_as_trig(eq)
    assert f(fu(t)) == cosh(2*x)
    e, f = hyper_as_trig(tanh(x + y))
    assert f(TR12(e)) == (tanh(x) + tanh(y))/(tanh(x)*tanh(y) + 1)

    d = Dummy()
    assert o(sinh(x), d) == I*sin(x*d)
    assert o(tanh(x), d) == I*tan(x*d)
    assert o(coth(x), d) == cot(x*d)/I
    assert o(cosh(x), d) == cos(x*d)
    for func in (sinh, cosh, tanh, coth):
        h = func(pi)
        assert i(o(h, d), d) == h
    # /!\ the _osborne functions are not meant to work
    # in the o(i(trig, d), d) direction so we just check
    # that they work as they are supposed to work
    assert i(cos(x*y), y) == cosh(x)
    assert i(sin(x*y), y) == sinh(x)/I
    assert i(tan(x*y), y) == tanh(x)/I
    assert i(cot(x*y), y) == coth(x)*I
    assert i(sec(x*y), y) == 1/cosh(x)
    assert i(csc(x*y), y) == I/sinh(x)

def test_simplifications():
    x = Symbol('x')
    assert sinh(asinh(x)) == x
    assert sinh(acosh(x)) == sqrt(x - 1) * sqrt(x + 1)
    assert sinh(atanh(x)) == x/sqrt(1 - x**2)
    assert sinh(acoth(x)) == 1/(sqrt(x - 1) * sqrt(x + 1))

    assert cosh(asinh(x)) == sqrt(1 + x**2)
    assert cosh(acosh(x)) == x
    assert cosh(atanh(x)) == 1/sqrt(1 - x**2)
    assert cosh(acoth(x)) == x/(sqrt(x - 1) * sqrt(x + 1))

    assert tanh(asinh(x)) == x/sqrt(1 + x**2)
    assert tanh(acosh(x)) == sqrt(x - 1) * sqrt(x + 1) / x
    assert tanh(atanh(x)) == x
    assert tanh(acoth(x)) == 1/x

    assert coth(asinh(x)) == sqrt(1 + x**2)/x
    assert coth(acosh(x)) == x/(sqrt(x - 1) * sqrt(x + 1))
    assert coth(atanh(x)) == 1/x
    assert coth(acoth(x)) == x

    assert csch(asinh(x)) == 1/x
    assert csch(acosh(x)) == 1/(sqrt(x - 1) * sqrt(x + 1))
    assert csch(atanh(x)) == sqrt(1 - x**2)/x
    assert csch(acoth(x)) == sqrt(x - 1) * sqrt(x + 1)

    assert sech(asinh(x)) == 1/sqrt(1 + x**2)
    assert sech(acosh(x)) == 1/x
    assert sech(atanh(x)) == sqrt(1 - x**2)
    assert sech(acoth(x)) == sqrt(x - 1) * sqrt(x + 1)/x

def test_tan_rewrite():
    neg_exp, pos_exp = exp(-x*I), exp(x*I)
    assert tan(x).rewrite(exp) == I*(neg_exp - pos_exp)/(neg_exp + pos_exp)
    assert tan(x).rewrite(sin) == 2*sin(x)**2/sin(2*x)
    assert tan(x).rewrite(cos) == -cos(x + S.Pi/2)/cos(x)
    assert tan(x).rewrite(cot) == 1/cot(x)
    assert tan(sinh(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, sinh(3)).n()
    assert tan(cosh(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, cosh(3)).n()
    assert tan(tanh(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, tanh(3)).n()
    assert tan(coth(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, coth(3)).n()
    assert tan(sin(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, sin(3)).n()
    assert tan(cos(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, cos(3)).n()
    assert tan(tan(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, tan(3)).n()
    assert tan(cot(x)).rewrite(
        exp).subs(x, 3).n() == tan(x).rewrite(exp).subs(x, cot(3)).n()
    assert tan(log(x)).rewrite(Pow) == I*(x**-I - x**I)/(x**-I + x**I)
    assert 0 == (cos(pi/15)*tan(pi/15) - sin(pi/15)).rewrite(pow)
    assert tan(pi/19).rewrite(pow) == tan(pi/19)
    assert tan(8*pi/19).rewrite(sqrt) == tan(8*pi/19)

def test_cot():
    assert cot(nan) == nan

    assert cot.nargs == FiniteSet(1)
    assert cot(oo*I) == -I
    assert cot(-oo*I) == I

    assert cot(0) == zoo
    assert cot(2*pi) == zoo

    assert cot(acot(x)) == x
    assert cot(atan(x)) == 1 / x
    assert cot(asin(x)) == sqrt(1 - x**2) / x
    assert cot(acos(x)) == x / sqrt(1 - x**2)
    assert cot(atan2(y, x)) == x/y

    assert cot(pi*I) == -coth(pi)*I
    assert cot(-pi*I) == coth(pi)*I
    assert cot(-2*I) == coth(2)*I

    assert cot(pi) == cot(2*pi) == cot(3*pi)
    assert cot(-pi) == cot(-2*pi) == cot(-3*pi)

    assert cot(pi/2) == 0
    assert cot(-pi/2) == 0
    assert cot(5*pi/2) == 0
    assert cot(7*pi/2) == 0

    assert cot(pi/3) == 1/sqrt(3)
    assert cot(-2*pi/3) == 1/sqrt(3)

    assert cot(pi/4) == S.One
    assert cot(-pi/4) == -S.One
    assert cot(17*pi/4) == S.One
    assert cot(-3*pi/4) == S.One

    assert cot(pi/6) == sqrt(3)
    assert cot(-pi/6) == -sqrt(3)
    assert cot(7*pi/6) == sqrt(3)
    assert cot(-5*pi/6) == sqrt(3)

    assert cot(x*I) == -coth(x)*I
    assert cot(k*pi*I) == -coth(k*pi)*I

    assert cot(r).is_real is True

    assert cot(a).is_algebraic is None
    assert cot(na).is_algebraic is False

    assert cot(10*pi/7) == cot(3*pi/7)
    assert cot(11*pi/7) == -cot(3*pi/7)
    assert cot(-11*pi/7) == cot(3*pi/7)

    assert cot(x).is_finite is None
    assert cot(r).is_finite is None
    i = Symbol('i', imaginary=True)
    assert cot(i).is_finite is True

    assert cot(x).subs(x, 3*pi) == zoo

def test_hyperbolic_simp():
    x, y = symbols('x,y')

    assert trigsimp(sinh(x)**2 + 1) == cosh(x)**2
    assert trigsimp(cosh(x)**2 - 1) == sinh(x)**2
    assert trigsimp(cosh(x)**2 - sinh(x)**2) == 1
    assert trigsimp(1 - tanh(x)**2) == 1/cosh(x)**2
    assert trigsimp(1 - 1/cosh(x)**2) == tanh(x)**2
    assert trigsimp(tanh(x)**2 + 1/cosh(x)**2) == 1
    assert trigsimp(coth(x)**2 - 1) == 1/sinh(x)**2
    assert trigsimp(1/sinh(x)**2 + 1) == 1/tanh(x)**2
    assert trigsimp(coth(x)**2 - 1/sinh(x)**2) == 1

    assert trigsimp(5*cosh(x)**2 - 5*sinh(x)**2) == 5
    assert trigsimp(5*cosh(x/2)**2 - 2*sinh(x/2)**2) == 3*cosh(x)/2 + S(7)/2

    assert trigsimp(sinh(x)/cosh(x)) == tanh(x)
    assert trigsimp(tanh(x)) == trigsimp(sinh(x)/cosh(x))
    assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
    assert trigsimp(2*tanh(x)*cosh(x)) == 2*sinh(x)
    assert trigsimp(coth(x)**3*sinh(x)**3) == cosh(x)**3
    assert trigsimp(y*tanh(x)**2/sinh(x)**2) == y/cosh(x)**2
    assert trigsimp(coth(x)/cosh(x)) == 1/sinh(x)

    for a in (pi/6*I, pi/4*I, pi/3*I):
        assert trigsimp(sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x + a)
        assert trigsimp(-sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x - a)

    e = 2*cosh(x)**2 - 2*sinh(x)**2
    assert trigsimp(log(e)) == log(2)

    assert trigsimp(cosh(x)**2*cosh(y)**2 - cosh(x)**2*sinh(y)**2 - sinh(x)**2,
            recursive=True) == 1
    assert trigsimp(sinh(x)**2*sinh(y)**2 - sinh(x)**2*cosh(y)**2 + cosh(x)**2,
            recursive=True) == 1

    assert abs(trigsimp(2.0*cosh(x)**2 - 2.0*sinh(x)**2) - 2.0) < 1e-10

    assert trigsimp(sinh(x)**2/cosh(x)**2) == tanh(x)**2
    assert trigsimp(sinh(x)**3/cosh(x)**3) == tanh(x)**3
    assert trigsimp(sinh(x)**10/cosh(x)**10) == tanh(x)**10
    assert trigsimp(cosh(x)**3/sinh(x)**3) == 1/tanh(x)**3

    assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
    assert trigsimp(cosh(x)**2/sinh(x)**2) == 1/tanh(x)**2
    assert trigsimp(cosh(x)**10/sinh(x)**10) == 1/tanh(x)**10

    assert trigsimp(x*cosh(x)*tanh(x)) == x*sinh(x)
    assert trigsimp(-sinh(x) + cosh(x)*tanh(x)) == 0

    assert tan(x) != 1/cot(x)  # cot doesn't auto-simplify

    assert trigsimp(tan(x) - 1/cot(x)) == 0
    assert trigsimp(3*tanh(x)**7 - 2/coth(x)**7) == tanh(x)**7

def test_cot():
    x, y = symbols('x,y')

    r = Symbol('r', real=True)

    k = Symbol('k', integer=True)

    assert cot(nan) == nan

    assert cot(oo*I) == -I
    assert cot(-oo*I) == I

    assert cot(0) == zoo
    assert cot(2*pi) == zoo

    assert cot(acot(x)) == x
    assert cot(atan(x)) == 1 / x
    assert cot(asin(x)) == sqrt(1 - x**2) / x
    assert cot(acos(x)) == x / sqrt(1 - x**2)
    assert cot(atan2(y, x)) == x/y

    assert cot(pi*I) == -coth(pi)*I
    assert cot(-pi*I) == coth(pi)*I
    assert cot(-2*I) == coth(2)*I

    assert cot(pi) == cot(2*pi) == cot(3*pi)
    assert cot(-pi) == cot(-2*pi) == cot(-3*pi)

    assert cot(pi/2) == 0
    assert cot(-pi/2) == 0
    assert cot(5*pi/2) == 0
    assert cot(7*pi/2) == 0

    assert cot(pi/3) == 1/sqrt(3)
    assert cot(-2*pi/3) == 1/sqrt(3)

    assert cot(pi/4) == S.One
    assert cot(-pi/4) == -S.One
    assert cot(17*pi/4) == S.One
    assert cot(-3*pi/4) == S.One

    assert cot(pi/6) == sqrt(3)
    assert cot(-pi/6) == -sqrt(3)
    assert cot(7*pi/6) == sqrt(3)
    assert cot(-5*pi/6) == sqrt(3)

    assert cot(x*I) == -coth(x)*I
    assert cot(k*pi*I) == -coth(k*pi)*I

    assert cot(r).is_real is True

    assert cot(10*pi/7) == cot(3*pi/7)
    assert cot(11*pi/7) == -cot(3*pi/7)
    assert cot(-11*pi/7) == cot(3*pi/7)

def test_derivs():
    x = Symbol('x')
    assert coth(x).diff(x) == -sinh(x)**(-2)
    assert sinh(x).diff(x) == cosh(x)
    assert cosh(x).diff(x) == sinh(x)
    assert tanh(x).diff(x) == -tanh(x)**2 + 1
    assert csch(x).diff(x) == -coth(x)*csch(x)
    assert sech(x).diff(x) == -tanh(x)*sech(x)
    assert acoth(x).diff(x) == 1/(-x**2 + 1)
    assert asinh(x).diff(x) == 1/sqrt(x**2 + 1)
    assert acosh(x).diff(x) == 1/sqrt(x**2 - 1)
    assert atanh(x).diff(x) == 1/(-x**2 + 1)

def test_cos_rewrite():
    assert cos(x).rewrite(exp) == exp(I * x) / 2 + exp(-I * x) / 2
    assert cos(x).rewrite(tan) == (1 - tan(x / 2) ** 2) / (1 + tan(x / 2) ** 2)
    assert cos(x).rewrite(cot) == -(1 - cot(x / 2) ** 2) / (1 + cot(x / 2) ** 2)
    assert cos(sinh(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, sinh(3)).n()
    assert cos(cosh(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, cosh(3)).n()
    assert cos(tanh(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, tanh(3)).n()
    assert cos(coth(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, coth(3)).n()
    assert cos(sin(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, sin(3)).n()
    assert cos(cos(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, cos(3)).n()
    assert cos(tan(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, tan(3)).n()
    assert cos(cot(x)).rewrite(exp).subs(x, 3).n() == cos(x).rewrite(exp).subs(x, cot(3)).n()
    assert cos(log(x)).rewrite(Pow) == x ** I / 2 + x ** -I / 2

def test_sin_rewrite():
    assert sin(x).rewrite(exp) == -I * (exp(I * x) - exp(-I * x)) / 2
    assert sin(x).rewrite(tan) == 2 * tan(x / 2) / (1 + tan(x / 2) ** 2)
    assert sin(x).rewrite(cot) == 2 * cot(x / 2) / (1 + cot(x / 2) ** 2)
    assert sin(sinh(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, sinh(3)).n()
    assert sin(cosh(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, cosh(3)).n()
    assert sin(tanh(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, tanh(3)).n()
    assert sin(coth(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, coth(3)).n()
    assert sin(sin(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, sin(3)).n()
    assert sin(cos(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, cos(3)).n()
    assert sin(tan(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, tan(3)).n()
    assert sin(cot(x)).rewrite(exp).subs(x, 3).n() == sin(x).rewrite(exp).subs(x, cot(3)).n()
    assert sin(log(x)).rewrite(Pow) == I * x ** -I / 2 - I * x ** I / 2

def test_trigsimp1a():
    assert trigsimp(sin(2)**2*cos(3)*exp(2)/cos(2)**2) == tan(2)**2*cos(3)*exp(2)
    assert trigsimp(tan(2)**2*cos(3)*exp(2)*cos(2)**2) == sin(2)**2*cos(3)*exp(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)*sin(2)) == cos(3)*exp(2)*cos(2)
    assert trigsimp(tan(2)*cos(3)*exp(2)/sin(2)) == cos(3)*exp(2)/cos(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)/cos(2)) == cos(3)*exp(2)/sin(2)
    assert trigsimp(cot(2)*cos(3)*exp(2)*tan(2)) == cos(3)*exp(2)
    assert trigsimp(sinh(2)*cos(3)*exp(2)/cosh(2)) == tanh(2)*cos(3)*exp(2)
    assert trigsimp(tanh(2)*cos(3)*exp(2)*cosh(2)) == sinh(2)*cos(3)*exp(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)*sinh(2)) == cosh(2)*cos(3)*exp(2)
    assert trigsimp(tanh(2)*cos(3)*exp(2)/sinh(2)) == cos(3)*exp(2)/cosh(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)/cosh(2)) == cos(3)*exp(2)/sinh(2)
    assert trigsimp(coth(2)*cos(3)*exp(2)*tanh(2)) == cos(3)*exp(2)

def test_cot_rewrite():
    x = Symbol('x')
    neg_exp, pos_exp = exp(-x*I), exp(x*I)
    assert cot(x).rewrite(exp) == I*(pos_exp+neg_exp)/(pos_exp-neg_exp)
    assert cot(x).rewrite(sin) == 2*sin(2*x)/sin(x)**2
    assert cot(x).rewrite(cos) == -cos(x)/cos(x + S.Pi/2)
    assert cot(x).rewrite(tan) == 1/tan(x)
    assert cot(sinh(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, sinh(3)).n()
    assert cot(cosh(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, cosh(3)).n()
    assert cot(tanh(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, tanh(3)).n()
    assert cot(coth(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, coth(3)).n()
    assert cot(sin(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, sin(3)).n()
    assert cot(tan(x)).rewrite(exp).subs(x, 3).n() == cot(x).rewrite(exp).subs(x, tan(3)).n()
    assert cot(log(x)).rewrite(Pow) == -I*(x**-I + x**I)/(x**-I - x**I)

def test_cot():
    assert cot(nan) == nan

    assert cot.nargs == FiniteSet(1)
    assert cot(oo*I) == -I
    assert cot(-oo*I) == I

    assert cot(0) == zoo
    assert cot(2*pi) == zoo

    assert cot(acot(x)) == x
    assert cot(atan(x)) == 1 / x
    assert cot(asin(x)) == sqrt(1 - x**2) / x
    assert cot(acos(x)) == x / sqrt(1 - x**2)
    assert cot(atan2(y, x)) == x/y

    assert cot(pi*I) == -coth(pi)*I
    assert cot(-pi*I) == coth(pi)*I
    assert cot(-2*I) == coth(2)*I

    assert cot(pi) == cot(2*pi) == cot(3*pi)
    assert cot(-pi) == cot(-2*pi) == cot(-3*pi)

    assert cot(pi/2) == 0
    assert cot(-pi/2) == 0
    assert cot(5*pi/2) == 0
    assert cot(7*pi/2) == 0

    assert cot(pi/3) == 1/sqrt(3)
    assert cot(-2*pi/3) == 1/sqrt(3)

    assert cot(pi/4) == S.One
    assert cot(-pi/4) == -S.One
    assert cot(17*pi/4) == S.One
    assert cot(-3*pi/4) == S.One

    assert cot(pi/6) == sqrt(3)
    assert cot(-pi/6) == -sqrt(3)
    assert cot(7*pi/6) == sqrt(3)
    assert cot(-5*pi/6) == sqrt(3)

    assert cot(x*I) == -coth(x)*I
    assert cot(k*pi*I) == -coth(k*pi)*I

    assert cot(r).is_real is True

    assert cot(10*pi/7) == cot(3*pi/7)
    assert cot(11*pi/7) == -cot(3*pi/7)
    assert cot(-11*pi/7) == cot(3*pi/7)

def test_sign_assumptions():
    p = Symbol('p', positive=True)
    n = Symbol('n', negative=True)
    assert sinh(n).is_negative is True
    assert sinh(p).is_positive is True
    assert cosh(n).is_positive is True
    assert cosh(p).is_positive is True
    assert tanh(n).is_negative is True
    assert tanh(p).is_positive is True
    assert csch(n).is_negative is True
    assert csch(p).is_positive is True
    assert sech(n).is_positive is True
    assert sech(p).is_positive is True
    assert coth(n).is_negative is True
    assert coth(p).is_positive is True

def test_hyper_as_trig():
    from sympy.simplify.fu import _osborne, _osbornei

    eq = sinh(x)**2 + cosh(x)**2
    t, f = hyper_as_trig(eq)
    assert f(fu(t)) == cosh(2*x)
    assert _osborne(cosh(x)) == cos(x)
    assert _osborne(sinh(x)) == I*sin(x)
    assert _osborne(tanh(x)) == I*tan(x)
    assert _osborne(coth(x)) == cot(x)/I
    assert _osbornei(cos(x)) == cosh(x)
    assert _osbornei(sin(x)) == sinh(x)/I
    assert _osbornei(tan(x)) == tanh(x)/I
    assert _osbornei(cot(x)) == coth(x)*I
    assert _osbornei(sec(x)) == 1/cosh(x)
    assert _osbornei(csc(x)) == I/sinh(x)