'Compute roots in linear, quadratic and binomial cases.'

@classmethod
@cacheit
def _roots_trivial(cls, poly, radicals):

    if (poly.degree() == 1):
        return roots_linear(poly)
    if (not radicals):
        return None
    if (poly.degree() == 2):
        return roots_quadratic(poly)
    elif ((poly.length() == 2) and poly.TC()):
        return roots_binomial(poly)
    else:
        return None
