x-1x=4 হলে,x2+1x2= এর মান কত ?
A
18
B
16
C
11
Correct Answer: 18
x2 + 1/x2 = ( x - 1/x )2 + 2* x* 1/x = ( x - 1/x )2 + 2 = 42 + 2 = 16 + 2 = 18