sin 90 + sin 50 cos 98 + cos 5e Establish the identity = tan (70). Which of the following statements establishes the identity? O A. 90 -50 2 sin 2 90 + 50 98 - 50 sin cos sin 90 + sin 50 = tan (70) cos 90 + cos 50 90 - 50 90 + 50 90 - 50 2 cos Cos Cos 2 OB. 90 - 50 2 sin 90 + 50 90 + 50 sin 2 cos sin 90 + sin 50 = tan (70) cos 90 + cos 50 90 + 50 90 - 50 90 + 50 2 cos cos cos 2 OC. 90 + 50 2 sin 2 90 - 50 90 + 50 sin cos sin 90 + sin 50 tan (70) cos 90 + cos 50 90 + 50 90 - 50 90 + 50 2 cos 2. cos cos 2.