udowodnij tożsamość Pola: a) sin2x cosx −−−−−−−−−−−−−− * −−−−−−−−−− = tg x/2 1+ cos2x 1+cosx b) 1+2tgx − tg²x 1 −−−−−−−−−−−−−−−−−− = −−−−−−−−− cos2x +sin2x cos² x c) cosx − cos 3x tgx = −−−−−−−−−−−−−−−−− sin 3x − sin x d) 1 −−−−−−−−−−−−−−−−−−−− = cos 2x 1+ tgx * tg2x e) 2 sinx − sin 2x −−−−−−−−−−−−−−−−−−−−−− = tg² x/2 2 sinx + sin 2x f) 1−tg² x 2 sin² x −1 = −−−−−−−−−−−−− 1+ tg²x