If $x + \frac{1}{x} = \sqrt{17}$, then find the value of $\frac{x^{4}-1}{x^{2}}$.
Answer: A
(X^4 - 1)/X^2 = X^2 - 1/X^2 = (X - 1/X)(X + 1/X). Since (X - 1/X)^2 = (X + 1/X)^2 - 4 = 17 - 4 = 13, X - 1/X = +/- sqrt13. Product = +/- sqrt13 x sqrt17 = +/- sqrt221. This is option A. Option A.
यदि $x + \frac{1}{x} = \sqrt{17}$ है, तो $\frac{x^{4}-1}{x^{2}}$ का मान ज्ञात कीजिए।
उत्तर: A
(X⁴ − 1)/X² = X² − 1/X² = (X − 1/X)(X + 1/X)। (X − 1/X)² = (X + 1/X)² − 4 = 17 − 4 = 13, अतः X − 1/X = ±√13। गुणनफल = ±√13 × √17 = ±√221। अतः सही विकल्प A है। विकल्प A।