x⁴ - x² + 1= 0 হয়, তবে x³ + 1/ x³ =?

x⁴ - x² + 1 = 0
বা, X⁴ + 1 = x²
বা, x² + 1/x² = 1
বা, (x + 1/x)² - 2.x.1/x) = 1
বা, (x + 1/x)² = 3
বা, (x + 1/x) = √3
এখন, x³ + 1/x³
= (x + 1/x)³ - 3.x.1/x (x + 1/x)
= (√3)³ - 3(√3)
= 3√3 - 3√3 = 0