def rot_axis3(theta):
    ct = cos(theta)
    st = sin(theta)
    lil = ((ct, st, 0),
           (-st, ct, 0),
           (0, 0, 1))
    return Matrix(lil)
Returns a rotation matrix for a rotation of theta (in radians) about
dataset/ETHPy150Open sympy/sympy/sympy/matrices/dense.py/rot_axis3