x4 + 2x2 + 1 = 5x2 হলে, \(x + \frac{1}{x}\) = কত ?

x⁴ + 2x² + 1 = 5x² হলে, \(x + \frac{1}{x}\) = কত ?

A \(\sqrt 3 \)

B 2

C 5

D \(\sqrt 5 \)

Solution

Correct Answer: Option D

x⁴+2x2 +1 = 5x2

বা, x⁴+1 = 3x²

বা, x² \((x2 + \frac{1}{{x2}}) = 3x2\) বা, \(x2 + \frac{1}{{x2}} = 3\) বা, \((x + \frac{1}{x})2 - 2.x.\frac{1}{x} = 3\) বা, \((x + \frac{1}{x})2\) = 3+2

\(x + \frac{1}{x} = \sqrt 5 \)

Solution

Practice More Questions on Our App!

Related Topics