def test_atan():
    x = Symbol("x", real=True)
    assert limit(atan(x)*sin(1/x), x, 0) == 0
    assert limit(atan(x) + sqrt(x + 1) - sqrt(x), x, oo) == pi/2
dataset/ETHPy150Open sympy/sympy/sympy/series/tests/test_limits.py/test_atan/original