def test_ADmath_tanhr():
f = ADmath.tanh(-5)
assert f == np.tanh(-5)
def test_ADmath_tanh():
f = ADmath.tanh(ADnum(-5, der=1))
assert f.val == np.tanh(-5)
assert f.der == 1 / (np.cosh(-5)**2)
assert len(f.graph) == 1