x4-x2-1 = 0 হলে x2 - (1/x2) = কত?

x⁴-x²-1 = 0 হলে x² - (1/x²) = কত?

B 1

C 2

D 4

Solution

Correct Answer: Option B

x⁴-x²-1 = 0

=> x⁴ - 1 =x²

=> x⁴-1/x²=1

=>x²-1/x²=1