def test_atan_rewrite():
assert atan(x).rewrite(log) == I*log((1 - I*x)/(1 + I*x))/2
assert atan(x).rewrite(asin) == (-asin(1/sqrt(x**2 + 1)) + pi/2)*sqrt(x**2)/x
assert atan(x).rewrite(acos) == sqrt(x**2)*acos(1/sqrt(x**2 + 1))/x
assert atan(x).rewrite(acot) == acot(1/x)
assert atan(x).rewrite(asec) == sqrt(x**2)*asec(sqrt(x**2 + 1))/x
assert atan(x).rewrite(acsc) == (-acsc(sqrt(x**2 + 1)) + pi/2)*sqrt(x**2)/x
def test_asin_rewrite():
assert asin(x).rewrite(log) == -I*log(I*x + sqrt(1 - x**2))
assert asin(x).rewrite(atan) == 2*atan(x/(1 + sqrt(1 - x**2)))
assert asin(x).rewrite(acos) == pi/2 - acos(x)
assert asin(x).rewrite(acot) == 2*acot((sqrt(-x**2 + 1) + 1)/x)
assert asin(x).rewrite(asec) == -asec(1/x) + pi/2
assert asin(x).rewrite(acsc) == acsc(1/x)
def test_acos_rewrite():
assert acos(x).rewrite(log) == pi/2 + I*log(I*x + sqrt(1 - x**2))
assert acos(x).rewrite(atan) == \
atan(sqrt(1 - x**2)/x) + (pi/2)*(1 - x*sqrt(1/x**2))
assert acos(0).rewrite(atan) == pi/2
assert acos(0.5).rewrite(atan) == acos(0.5).rewrite(log)
assert acos(x).rewrite(asin) == pi/2 - asin(x)
assert acos(x).rewrite(acot) == -2*acot((sqrt(-x**2 + 1) + 1)/x) + pi/2
assert acos(x).rewrite(asec) == asec(1/x)
assert acos(x).rewrite(acsc) == -acsc(1/x) + pi/2
def test_aseries():
def t(n, v, d, e):
assert abs(n(1/v).evalf(strict=False) -
n(1/x).series(x, dir=d).removeO().subs({x: v})) < e
t(atan, 0.1, '+', 1e-5)
t(atan, -0.1, '-', 1e-5)
t(acot, 0.1, '+', 1e-5)
t(acot, -0.1, '-', 1e-5)
pytest.raises(PoleError, lambda: atan(y/x).series(x, n=1))
pytest.raises(PoleError, lambda: acot(y/x).series(x, n=1))
def test_inverses():
pytest.raises(AttributeError, lambda: sin(x).inverse())
pytest.raises(AttributeError, lambda: cos(x).inverse())
assert tan(x).inverse() == atan
assert cot(x).inverse() == acot
pytest.raises(AttributeError, lambda: csc(x).inverse())
pytest.raises(AttributeError, lambda: sec(x).inverse())
assert asin(x).inverse() == sin
assert acos(x).inverse() == cos
assert atan(x).inverse() == tan
assert acot(x).inverse() == cot
def test_acot_rewrite():
assert acot(x).rewrite(log) == I*log((x - I)/(x + I))/2
assert acot(x).rewrite(asin) == x*(-asin(sqrt(-x**2)/sqrt(-x**2 - 1)) + pi/2)*sqrt(x**(-2))
assert acot(x).rewrite(acos) == x*sqrt(x**(-2))*acos(sqrt(-x**2)/sqrt(-x**2 - 1))
assert acot(x).rewrite(atan) == atan(1/x)
assert acot(x).rewrite(asec) == x*sqrt(x**(-2))*asec(sqrt((x**2 + 1)/x**2))
assert acot(x).rewrite(acsc) == x*(-acsc(sqrt((x**2 + 1)/x**2)) + pi/2)*sqrt(x**(-2))
def test_leading_terms():
for func in [sin, cos, tan, cot, asin, acos, atan, acot]:
for arg in (1/x, Rational(1, 2)):
eq = func(arg)
assert eq.as_leading_term(x) == eq
# issue sympy/sympy#5272
assert sin(x).as_leading_term(x) == x
assert cos(x).as_leading_term(x) == 1
assert tan(x).as_leading_term(x) == x
assert cot(x).as_leading_term(x) == 1/x
assert asin(x).as_leading_term(x) == x
assert acos(x).as_leading_term(x) == x
assert atan(x).as_leading_term(x) == x
assert acot(x).as_leading_term(x) == x
def test_acsc():
assert acsc(nan) == nan
assert acsc(1) == pi/2
assert acsc(-1) == -pi/2
assert acsc(oo) == 0
assert acsc(-oo) == 0
assert acsc(zoo) == 0
assert acsc(x).diff(x) == -1/(x**2*sqrt(1 - 1/x**2))
assert acsc(x).as_leading_term(x) == log(x)
assert acsc(x).rewrite(log) == -I*log(sqrt(1 - 1/x**2) + I/x)
assert acsc(x).rewrite(asin) == asin(1/x)
assert acsc(x).rewrite(acos) == -acos(1/x) + pi/2
assert acsc(x).rewrite(atan) == (-atan(sqrt(x**2 - 1)) + pi/2)*sqrt(x**2)/x
assert acsc(x).rewrite(acot) == (-acot(1/sqrt(x**2 - 1)) + pi/2)*sqrt(x**2)/x
assert acsc(x).rewrite(asec) == -asec(x) + pi/2
pytest.raises(ArgumentIndexError, lambda: acsc(x).fdiff(2))
assert acsc(x).as_leading_term(x) == log(x)
assert acsc(1/x).as_leading_term(x) == acsc(1/x)
def test_asec():
z = Symbol('z', zero=True)
assert asec(z) == zoo
assert asec(nan) == nan
assert asec(1) == 0
assert asec(-1) == pi
assert asec(oo) == pi/2
assert asec(-oo) == pi/2
assert asec(zoo) == pi/2
assert asec(x).diff(x) == 1/(x**2*sqrt(1 - 1/x**2))
assert asec(x).as_leading_term(x) == log(x)
assert asec(x).rewrite(log) == I*log(sqrt(1 - 1/x**2) + I/x) + pi/2
assert asec(x).rewrite(asin) == -asin(1/x) + pi/2
assert asec(x).rewrite(acos) == acos(1/x)
assert asec(x).rewrite(atan) == (2*atan(x + sqrt(x**2 - 1)) - pi/2)*sqrt(x**2)/x
assert asec(x).rewrite(acot) == (2*acot(x - sqrt(x**2 - 1)) - pi/2)*sqrt(x**2)/x
assert asec(x).rewrite(acsc) == -acsc(x) + pi/2
pytest.raises(ArgumentIndexError, lambda: asec(x).fdiff(2))
assert asec(x).as_leading_term(x) == log(x)
assert asec(1/x).as_leading_term(x) == asec(1/x)
def test_aseries_trig():
assert gruntz(1/log(atan(x)), x) == -1/(-log(pi) + log(2))
assert gruntz(1/acot(-x), x) == -oo
def test_aseries_trig():
assert gruntz(1 / log(atan(x)), x) == -1 / (-log(pi) + log(2))
assert gruntz(1 / acot(-x), x) == -oo
def test_aseries_trig():
assert limit(1/log(atan(x)), x, oo) == -1/(-log(pi) + log(2))
assert limit(1/acot(-x), x, oo) == -oo
def test_Function():
assert mathematica_code(f(x, y, z)) == 'f[x, y, z]'
assert mathematica_code(sin(x)**cos(x)) == 'Sin[x]^Cos[x]'
assert mathematica_code(sign(x)) == 'Sign[x]'
assert mathematica_code(atanh(x),
user_functions={'atanh':
'ArcTanh'}) == 'ArcTanh[x]'
assert (mathematica_code(meijerg(
((1, 1), (3, 4)), ((1, ), ()),
x)) == 'MeijerG[{{1, 1}, {3, 4}}, {{1}, {}}, x]')
assert (mathematica_code(hyper(
(1, 2, 3), (3, 4), x)) == 'HypergeometricPFQ[{1, 2, 3}, {3, 4}, x]')
assert mathematica_code(Min(x, y)) == 'Min[x, y]'
assert mathematica_code(Max(x, y)) == 'Max[x, y]'
assert mathematica_code(Max(x,
2)) == 'Max[2, x]' # issue sympy/sympy#15344
assert mathematica_code(binomial(x, y)) == 'Binomial[x, y]'
assert mathematica_code(log(x)) == 'Log[x]'
assert mathematica_code(tan(x)) == 'Tan[x]'
assert mathematica_code(cot(x)) == 'Cot[x]'
assert mathematica_code(asin(x)) == 'ArcSin[x]'
assert mathematica_code(acos(x)) == 'ArcCos[x]'
assert mathematica_code(atan(x)) == 'ArcTan[x]'
assert mathematica_code(acot(x)) == 'ArcCot[x]'
assert mathematica_code(sinh(x)) == 'Sinh[x]'
assert mathematica_code(cosh(x)) == 'Cosh[x]'
assert mathematica_code(tanh(x)) == 'Tanh[x]'
assert mathematica_code(coth(x)) == 'Coth[x]'
assert mathematica_code(asinh(x)) == 'ArcSinh[x]'
assert mathematica_code(acosh(x)) == 'ArcCosh[x]'
assert mathematica_code(atanh(x)) == 'ArcTanh[x]'
assert mathematica_code(acoth(x)) == 'ArcCoth[x]'
assert mathematica_code(sech(x)) == 'Sech[x]'
assert mathematica_code(csch(x)) == 'Csch[x]'
assert mathematica_code(erf(x)) == 'Erf[x]'
assert mathematica_code(erfi(x)) == 'Erfi[x]'
assert mathematica_code(erfc(x)) == 'Erfc[x]'
assert mathematica_code(conjugate(x)) == 'Conjugate[x]'
assert mathematica_code(re(x)) == 'Re[x]'
assert mathematica_code(im(x)) == 'Im[x]'
assert mathematica_code(polygamma(x, y)) == 'PolyGamma[x, y]'
assert mathematica_code(factorial(x)) == 'Factorial[x]'
assert mathematica_code(factorial2(x)) == 'Factorial2[x]'
assert mathematica_code(rf(x, y)) == 'Pochhammer[x, y]'
assert mathematica_code(gamma(x)) == 'Gamma[x]'
assert mathematica_code(zeta(x)) == 'Zeta[x]'
assert mathematica_code(Heaviside(x)) == 'UnitStep[x]'
assert mathematica_code(fibonacci(x)) == 'Fibonacci[x]'
assert mathematica_code(polylog(x, y)) == 'PolyLog[x, y]'
assert mathematica_code(loggamma(x)) == 'LogGamma[x]'
assert mathematica_code(uppergamma(x, y)) == 'Gamma[x, y]'
class MyFunc1(Function):
@classmethod
def eval(cls, x):
pass
class MyFunc2(Function):
@classmethod
def eval(cls, x, y):
pass
pytest.raises(
ValueError,
lambda: mathematica_code(MyFunc1(x),
user_functions={'MyFunc1': ['Myfunc1']}))
assert mathematica_code(MyFunc1(x),
user_functions={'MyFunc1':
'Myfunc1'}) == 'Myfunc1[x]'
assert mathematica_code(
MyFunc2(x, y),
user_functions={'MyFunc2':
[(lambda *x: False, 'Myfunc2')]}) == 'MyFunc2[x, y]'
def test_acot():
assert acot(nan) == nan
assert acot.nargs == FiniteSet(1)
assert acot(-oo) == 0
assert acot(oo) == 0
assert acot(1) == pi/4
assert acot(0) == pi/2
assert acot(sqrt(3)/3) == pi/3
assert acot(1/sqrt(3)) == pi/3
assert acot(-1/sqrt(3)) == -pi/3
assert acot(x).diff(x) == -1/(1 + x**2)
assert acot(r).is_extended_real is True
assert acot(I*pi) == -I*acoth(pi)
assert acot(-2*I) == I*acoth(2)
assert acot(x).is_positive is None
assert acot(p).is_positive is True
assert acot(I).is_positive is False
assert acot(0, evaluate=False).is_rational is False
q = Symbol('q', rational=True)
assert acot(q).is_rational is False
assert acot(x).is_rational is None
pytest.raises(ArgumentIndexError, lambda: acot(x).fdiff(2))
def test_cos():
x, y = symbols('x y')
assert cos.nargs == FiniteSet(1)
assert cos(nan) == nan
assert cos(oo) == cos(oo, evaluate=False)
assert cos(oo*I) == oo
assert cos(-oo*I) == oo
assert cos(0) == 1
assert cos(acos(x)) == x
assert cos(atan(x)) == 1 / sqrt(1 + x**2)
assert cos(asin(x)) == sqrt(1 - x**2)
assert cos(acot(x)) == 1 / sqrt(1 + 1 / x**2)
assert cos(atan2(y, x)) == x / sqrt(x**2 + y**2)
assert cos(pi*I) == cosh(pi)
assert cos(-pi*I) == cosh(pi)
assert cos(-2*I) == cosh(2)
assert cos(pi/2) == 0
assert cos(-pi/2) == 0
assert cos(pi/2) == 0
assert cos(-pi/2) == 0
assert cos((-3*10**73 + 1)*pi/2) == 0
assert cos((7*10**103 + 1)*pi/2) == 0
n = symbols('n', integer=True, even=False)
e = symbols('e', even=True)
assert cos(pi*n/2) == 0
assert cos(pi*e/2) == (-1)**(e/2)
assert cos(pi) == -1
assert cos(-pi) == -1
assert cos(2*pi) == 1
assert cos(5*pi) == -1
assert cos(8*pi) == 1
assert cos(pi/3) == Rational(1, 2)
assert cos(-2*pi/3) == Rational(-1, 2)
assert cos(pi/4) == sqrt(2)/2
assert cos(-pi/4) == sqrt(2)/2
assert cos(11*pi/4) == -sqrt(2)/2
assert cos(-3*pi/4) == -sqrt(2)/2
assert cos(pi/6) == sqrt(3)/2
assert cos(-pi/6) == sqrt(3)/2
assert cos(7*pi/6) == -sqrt(3)/2
assert cos(-5*pi/6) == -sqrt(3)/2
assert cos(1*pi/5) == (sqrt(5) + 1)/4
assert cos(2*pi/5) == (sqrt(5) - 1)/4
assert cos(3*pi/5) == -cos(2*pi/5)
assert cos(4*pi/5) == -cos(1*pi/5)
assert cos(6*pi/5) == -cos(1*pi/5)
assert cos(8*pi/5) == cos(2*pi/5)
assert cos(-1273*pi/5) == -cos(2*pi/5)
assert cos(pi/8) == sqrt((2 + sqrt(2))/4)
assert cos(pi/12) == sqrt(2)/4 + sqrt(6)/4
assert cos(5*pi/12) == -sqrt(2)/4 + sqrt(6)/4
assert cos(7*pi/12) == sqrt(2)/4 - sqrt(6)/4
assert cos(11*pi/12) == -sqrt(2)/4 - sqrt(6)/4
assert cos(104*pi/105) == -cos(pi/105)
assert cos(106*pi/105) == -cos(pi/105)
assert cos(-104*pi/105) == -cos(pi/105)
assert cos(-106*pi/105) == -cos(pi/105)
assert cos(x*I) == cosh(x)
assert cos(k*pi*I) == cosh(k*pi)
assert cos(r).is_real
assert cos(c).is_complex
assert cos(0, evaluate=False).is_algebraic
assert cos(a).is_algebraic is None
assert cos(na).is_algebraic is False
q = Symbol('q', rational=True)
assert cos(pi*q).is_algebraic
assert cos(2*pi/7).is_algebraic
qz = Symbol('qz', zero=True)
qn = Symbol('qn', rational=True, nonzero=True)
assert cos(qz).is_rational
assert cos(0, evaluate=False).is_rational
assert cos(qn).is_rational is False
assert cos(q).is_rational is None
assert cos(k*pi) == (-1)**k
assert cos(2*k*pi) == 1
for d in list(range(1, 22)) + [60, 85]:
for n in range(2*d + 1):
x = n*pi/d
e = abs( float(cos(x)) - cos(float(x)) )
assert e < 1e-12
assert cos(z).taylor_term(2, z, *(1, 0)) == -z**2/2
pytest.raises(ArgumentIndexError, lambda: cos(z).fdiff(2))
def test_sin():
x, y = symbols('x y')
assert sin.nargs == FiniteSet(1)
assert sin(nan) == nan
assert sin(oo*I) == oo*I
assert sin(-oo*I) == -oo*I
assert sin(oo).args[0] == oo
assert sin(0) == 0
assert sin(asin(x)) == x
assert sin(atan(x)) == x / sqrt(1 + x**2)
assert sin(acos(x)) == sqrt(1 - x**2)
assert sin(acot(x)) == 1 / (sqrt(1 + 1 / x**2) * x)
assert sin(atan2(y, x)) == y / sqrt(x**2 + y**2)
assert sin(pi*I) == sinh(pi)*I
assert sin(-pi*I) == -sinh(pi)*I
assert sin(-2*I) == -sinh(2)*I
assert sin(pi) == 0
assert sin(-pi) == 0
assert sin(2*pi) == 0
assert sin(-2*pi) == 0
assert sin(-3*10**73*pi) == 0
assert sin(7*10**103*pi) == 0
assert sin(pi/2) == 1
assert sin(-pi/2) == -1
assert sin(5*pi/2) == 1
assert sin(7*pi/2) == -1
ne = symbols('ne', integer=True, even=False)
e = symbols('e', even=True)
assert sin(pi*ne/2) == (-1)**(ne/2 - Rational(1, 2))
assert sin(pi*k/2).func == sin
assert sin(pi*e/2) == 0
assert sin(pi*k) == 0
assert sin(pi*k).subs({k: 3}) == sin(pi*k/2).subs({k: 6}) # issue sympy/sympy#8298
assert sin(pi/2*cos(k*pi)) == (-1)**k
assert sin(pi/3) == sqrt(3)/2
assert sin(-2*pi/3) == -sqrt(3)/2
assert sin(pi/4) == sqrt(2)/2
assert sin(-pi/4) == -sqrt(2)/2
assert sin(17*pi/4) == sqrt(2)/2
assert sin(-3*pi/4) == -sqrt(2)/2
assert sin(pi/6) == Rational(1, 2)
assert sin(-pi/6) == Rational(-1, 2)
assert sin(7*pi/6) == Rational(-1, 2)
assert sin(-5*pi/6) == Rational(-1, 2)
assert sin(1*pi/5) == sqrt((5 - sqrt(5)) / 8)
assert sin(2*pi/5) == sqrt((5 + sqrt(5)) / 8)
assert sin(3*pi/5) == sin(2*pi/5)
assert sin(4*pi/5) == sin(1*pi/5)
assert sin(6*pi/5) == -sin(1*pi/5)
assert sin(8*pi/5) == -sin(2*pi/5)
assert sin(-1273*pi/5) == -sin(2*pi/5)
assert sin(pi/8) == sqrt((2 - sqrt(2))/4)
assert sin(pi/10) == -Rational(1, 4) + sqrt(5)/4
assert sin(pi/12) == -sqrt(2)/4 + sqrt(6)/4
assert sin(5*pi/12) == sqrt(2)/4 + sqrt(6)/4
assert sin(-7*pi/12) == -sqrt(2)/4 - sqrt(6)/4
assert sin(-11*pi/12) == sqrt(2)/4 - sqrt(6)/4
assert sin(104*pi/105) == sin(pi/105)
assert sin(106*pi/105) == -sin(pi/105)
assert sin(-104*pi/105) == -sin(pi/105)
assert sin(-106*pi/105) == sin(pi/105)
assert sin(x*I) == sinh(x)*I
assert sin(k*pi) == 0
assert sin(17*k*pi) == 0
assert sin(k*pi*I) == sinh(k*pi)*I
assert sin(r).is_real
assert sin(c).is_complex
assert sin(0, evaluate=False).is_algebraic
assert sin(a).is_algebraic is None
assert sin(na).is_algebraic is False
q = Symbol('q', rational=True)
assert sin(pi*q).is_algebraic
qz = Symbol('qz', zero=True)
qn = Symbol('qn', rational=True, nonzero=True)
assert sin(qz).is_rational
assert sin(0, evaluate=False).is_rational
assert sin(qn).is_rational is False
assert sin(q).is_rational is None # issue sympy/sympy#8653
assert isinstance(sin( re(x) - im(y)), sin) is True
assert isinstance(sin(-re(x) + im(y)), sin) is False
for d in list(range(1, 22)) + [60, 85]:
for n in range(d*2 + 1):
x = n*pi/d
e = abs( float(sin(x)) - sin(float(x)) )
assert e < 1e-12
assert sin(z).taylor_term(3, z, *(z, 0)) == -z**3/6
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) == +1
assert cot(-pi/4) == -1
assert cot(17*pi/4) == 1
assert cot(-3*pi/4) == 1
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(pi/8).simplify() == 1 + sqrt(2)
assert cot(3*pi/8).simplify() == -1 + sqrt(2)
assert cot(5*pi/8).simplify() == 1 - sqrt(2)
assert cot(7*pi/8).simplify() == -1 - sqrt(2)
assert cot(pi/12).simplify() == sqrt(3) + 2
assert cot(5*pi/12).simplify() == -sqrt(3) + 2
assert cot(7*pi/12).simplify() == sqrt(3) - 2
assert cot(11*pi/12).simplify() == -sqrt(3) - 2
assert cot(pi/24).radsimp() == sqrt(2) + sqrt(3) + 2 + sqrt(6)
assert cot(5*pi/24).radsimp() == -sqrt(2) - sqrt(3) + 2 + sqrt(6)
assert cot(7*pi/24).radsimp() == -sqrt(2) + sqrt(3) - 2 + sqrt(6)
assert cot(11*pi/24).radsimp() == sqrt(2) - sqrt(3) - 2 + sqrt(6)
assert cot(13*pi/24).radsimp() == -sqrt(2) + sqrt(3) + 2 - sqrt(6)
assert cot(17*pi/24).radsimp() == sqrt(2) - sqrt(3) + 2 - sqrt(6)
assert cot(19*pi/24).radsimp() == sqrt(2) + sqrt(3) - 2 - sqrt(6)
assert cot(23*pi/24).radsimp() == -sqrt(2) - sqrt(3) - 2 - sqrt(6)
assert 1 == (cot(4*pi/15)*sin(4*pi/15)/cos(4*pi/15)).ratsimp()
assert cot(x*I) == -coth(x)*I
assert cot(k*pi*I) == -coth(k*pi)*I
ni = Symbol('ni', noninteger=True)
assert cot(pi*ni/2).is_extended_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(39*pi/34) == cot(5*pi/34)
assert cot(-41*pi/34) == -cot(7*pi/34)
assert cot(x).is_finite is None
assert cot(r).is_finite is None
i = Symbol('i', imaginary=True, nonzero=True)
assert cot(i).is_finite is True
assert cot(x).subs({x: 3*pi}) == zoo
pytest.raises(ArgumentIndexError, lambda: cot(x).fdiff(2))
# issue sympy/sympy#4547
assert cot(x).fdiff() == -1 - cot(x)**2
def test_tan():
assert tan(nan) == nan
assert tan.nargs == FiniteSet(1)
assert tan(oo*I) == I
assert tan(-oo*I) == -I
assert tan(0) == 0
assert tan(atan(x)) == x
assert tan(asin(x)) == x / sqrt(1 - x**2)
assert tan(acos(x)) == sqrt(1 - x**2) / x
assert tan(acot(x)) == 1 / x
assert tan(atan2(y, x)) == y/x
assert tan(pi*I) == tanh(pi)*I
assert tan(-pi*I) == -tanh(pi)*I
assert tan(-2*I) == -tanh(2)*I
assert tan(pi) == 0
assert tan(-pi) == 0
assert tan(2*pi) == 0
assert tan(-2*pi) == 0
assert tan(-3*10**73*pi) == 0
assert tan(pi/2) == zoo
assert tan(3*pi/2) == zoo
assert tan(pi/3) == sqrt(3)
assert tan(-2*pi/3) == sqrt(3)
assert tan(+pi/4) == +1
assert tan(-pi/4) == -1
assert tan(17*pi/4) == 1
assert tan(-3*pi/4) == 1
assert tan(pi/6) == 1/sqrt(3)
assert tan(-pi/6) == -1/sqrt(3)
assert tan(7*pi/6) == 1/sqrt(3)
assert tan(-5*pi/6) == 1/sqrt(3)
assert tan(pi/8).expand() == -1 + sqrt(2)
assert tan(3*pi/8).expand() == 1 + sqrt(2)
assert tan(5*pi/8).expand() == -1 - sqrt(2)
assert tan(7*pi/8).expand() == 1 - sqrt(2)
assert tan(pi/12) == -sqrt(3) + 2
assert tan(5*pi/12) == sqrt(3) + 2
assert tan(7*pi/12) == -sqrt(3) - 2
assert tan(11*pi/12) == sqrt(3) - 2
assert tan(pi/24).radsimp() == -2 - sqrt(3) + sqrt(2) + sqrt(6)
assert tan(5*pi/24).radsimp() == -2 + sqrt(3) - sqrt(2) + sqrt(6)
assert tan(7*pi/24).radsimp() == 2 - sqrt(3) - sqrt(2) + sqrt(6)
assert tan(11*pi/24).radsimp() == 2 + sqrt(3) + sqrt(2) + sqrt(6)
assert tan(13*pi/24).radsimp() == -2 - sqrt(3) - sqrt(2) - sqrt(6)
assert tan(17*pi/24).radsimp() == -2 + sqrt(3) + sqrt(2) - sqrt(6)
assert tan(19*pi/24).radsimp() == 2 - sqrt(3) + sqrt(2) - sqrt(6)
assert tan(23*pi/24).radsimp() == 2 + sqrt(3) - sqrt(2) - sqrt(6)
assert 1 == (tan(8*pi/15)*cos(8*pi/15)/sin(8*pi/15)).ratsimp()
assert tan(x*I) == tanh(x)*I
assert tan(k*pi) == 0
assert tan(17*k*pi) == 0
assert tan(k*pi*I) == tanh(k*pi)*I
ni = Symbol('ni', noninteger=True)
assert tan(ni*pi/2).is_real is True
assert tan(0, evaluate=False).is_algebraic
assert tan(a).is_algebraic is None
assert tan(na).is_algebraic is False
qz = Symbol('qz', zero=True)
qn = Symbol('qn', rational=True, nonzero=True)
assert tan(qz).is_rational
assert tan(0, evaluate=False).is_rational
assert tan(qn).is_rational is False
assert tan(x).is_rational is None
assert tan(qz).is_algebraic
assert tan(10*pi/7, evaluate=False).is_algebraic
assert tan(pi*k/2).is_algebraic is None
assert tan(10*pi/7) == tan(3*pi/7)
assert tan(11*pi/7) == -tan(3*pi/7)
assert tan(-11*pi/7) == tan(3*pi/7)
assert tan(15*pi/14) == tan(pi/14)
assert tan(-15*pi/14) == -tan(pi/14)
pytest.raises(ArgumentIndexError, lambda: tan(x).fdiff(2))
