def _eval_rewrite_as_cot(self, arg):
cot_half = S.Cot(S.Half * arg)**2
return (cot_half - 1) / (cot_half + 1)
def _eval_rewrite_as_cot(self, arg):
return 1 / S.Cot(arg)
def _eval_rewrite_as_cot(self, arg):
cot_half = S.Cot(S.Half * arg)
return 2 * cot_half / (1 + cot_half**2)