If $(x + \frac{1}{x}) = 8.5$, what is the value of $(x^2 + \frac{1}{x^2})$ ?
Answer & explanation
Correct answer: option 1
If $K+\frac{1}{K}=n$
then, $K^2+\frac{1}{K^2}$ = n2 – 2 × k × \(\frac{1}{k}\)
If $(x + \frac{1}{x}) = 8.5$
$(x^2 + \frac{1}{x^2})$ = (8.5)2 – 2
$(x^2 + \frac{1}{x^2})$ = 72.25 - 2 = 70.25