\[ E = \frac{E_0}{3} \implies V = \frac{V_0}{3} \]
\[ \frac{V_0}{3} = V_0 e^{-\frac{t}{\tau}} \]
\[ t = \tau \ln 3 \]
\[ 6.6 \times 10^{-6} = R (1.5 \times 10^{-6})(1.1) \]\[ R = \frac{6.6}{1.5} = 4 \, \Omega \]
Let $ P_n = \alpha^n + \beta^n $, $ n \in \mathbb{N} $. If $ P_{10} = 123,\ P_9 = 76,\ P_8 = 47 $ and $ P_1 = 1 $, then the quadratic equation having roots $ \alpha $ and $ \frac{1}{\beta} $ is: