x - 1/x = 2 হলে, x4 + 1/x4 = কত?

প্রশ্ন: x - 1/x = 2 হলে, x4 + 1/x4 = কত?সমাধান: x - 1/x = 2এখন x4 + 1/x4 = (x2)2 + (1/x2)2= (x2 + 1/x2)2 - 2.x2.1/x2= {(x - 1/x)2 + 2x.1/x}2 - 2= (22 + 2)2 - 2= 62 - 2= 36 - 2= 34