If x = a+ 1a and y = a-1a then x4+y4-2x2y2=? ক 4 খ 8 গ 16 ঘ None of these If x = a+ 1a and y = a-1a then x4+y4-2x2y2=? সঠিক উত্তর 16 x4+y4-2x2y2 Bissoy MCQ Team Nov 19, 2024