Two equations are shown, where a > 0.

Answer:
b = 1/512
Step-by-step explanation:
[tex] {a}^{2} = \frac{1}{64} \\ \\ a = \sqrt{ \frac{1}{64} } \\ \\ a = \frac{1}{8} [/tex]
now,
[tex] {b}^{3} = a \\ \\ {b}^{3} = \frac{1}{8} \\ \\ b = \sqrt{ \frac{1}{8} } \\ \\ b = \frac{1}{512} [/tex]