[tex]a_1 = \frac{1}{4}\\a_2 = \frac{1}{16}\\a_3 = \frac{1}{64}\\q = ?\\a_4=?\\a_5 = ?\\\\q = \frac{a_2}{a_1} = \frac{\frac{1}{16}}{\frac{1}{4}} = \frac{1}{4}\\\\\\a_{n} = a_1\cdot q^{n-1}\\\\a_4 = a_1\cdot q^{3}=\frac{1}{4}\cdot(\frac{1}{4})^{3} = \frac{1}{4^{4}} = \frac{1}{256}\\\\a_5 = a_1\cdot q^{4} = \frac{1}{4}\cdot(\frac{1}{4})^{4} = \frac{1}{4^{5}} = \frac{1}{1024}[/tex]
