If \(\sqrt {x}\) - \(\frac{1}{\sqrt {x}}\) = 4
Find x2 + \(\frac{1}{x^2}\)
Answer & explanation
Correct answer: option 3
Sq. on both sides
(\(\sqrt {x}\) - \(\frac{1}{\sqrt {x}}\))2 = (4)2
x + \(\frac{1}{x}\) - 2 = 16
x + \(\frac{1}{x}\) = 18
⇒ x2 + \(\frac{1}{x^2}\) = (18)2 - 2 = 322