The equation x^{5}-2 x^{4}-1=0 has five complex roots r_{1}, r_{2}, r_{3}, r_{4}, r_{5}. Find the value of
\frac{1}{r_{1}^{8}}+\frac{1}{r_{2}^{8}}+\frac{1}{r_{3}^{8}}+\frac{1}{r_{4}^{8}}+\frac{1}{r_{5}^{8}}
The equation x^{5}-2 x^{4}-1=0 has five complex roots r_{1}, r_{2}, r_{3}, r_{4}, r_{5}. Find the value of