Given that x8 - 34x4 + 1 = 0, x > 0, what is the value of (x3 + x-3)?

Answer: Option A

$$\begin{array}{rl}& x^4\left(x^4-34+\frac{1}{x^4}\right)=0\\ & x^4+\frac{1}{x^4}=34\\ & x^4+\frac{1}{x^4}+2=36\\ & x^2+\frac{1}{x^2}=6\\ & x+\frac{1}{x}=\sqrt{8}\\ & x^3+\frac{1}{x^3}=8\sqrt{8}-3\sqrt{8}\\ & x^3+\frac{1}{x^3}=5\sqrt{8}\end{array}$$