x-1/x = 2 হলে, x4 + 1/x4 = কত ?
সমাধান
সঠিক উত্তর: Option D
প্রদত্ত রাশি = x4 + 1/x4 = (x2)2 + (1/x2)2
=> ( x2 + 1/x2)2 - 2.x2.1/x2
=> {(x-1/x)2 + 2.x.1/x2} - 2
=> { 22 + 2}2 - 2
=> (4+2)2 - 2
=> 62 - 2
=> 36-2
=> 34
=> ( x2 + 1/x2)2 - 2.x2.1/x2
=> {(x-1/x)2 + 2.x.1/x2} - 2
=> { 22 + 2}2 - 2
=> (4+2)2 - 2
=> 62 - 2
=> 36-2
=> 34
