x2 + (1/x)2 = 5 হলে, x6 + (1/x)6 এর মান কত?

x² + (1/x)² = 5 হলে, x⁶ + (1/x)⁶ এর মান কত?

A 110

B 120

C 130

D 140

Correct Answer: Option A

x² + (1/x)² = 5 হলে,
x⁶ + (1/x)⁶
= (x²)³ + (1/x²)³
= (x²+ (1/x)²)³ - 3 x2 (1/x²) (x²+ (1/x)²)
= 5³ - 15
= 125 - 15
= 110