x²+1 = x√2 হলে x² + 1/x² = কত?
সমাধান
সঠিক উত্তর: Option C
x² + 1 = x√2
=> (x²+1)/x = √2
=> x + 1/x = √2
এখন, x² + 1/x2 = (x + 1/x)² - 2.x.1/x
=(√2)² - 2
= 2 - 2
= 0
=> (x²+1)/x = √2
=> x + 1/x = √2
এখন, x² + 1/x2 = (x + 1/x)² - 2.x.1/x
=(√2)² - 2
= 2 - 2
= 0
