Trong khoảng (0, 2 pi], phương trình cos2x+sin2x=0 có tập nghiệm là

You are studying for your final exam of the semester. up to this point, you received 3 exam scores of 67%, 68%, and 78%. to receive a grade of c in the class, you must have an average exam score between 70% and 79% for all 4 exams including the final.