Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
Question:
Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
Answer:
Let's think step by step.

user
\frac{6}{7}
Evaluate
\[\sum_{n = 0}^\infty \frac{\cos n \theta}{2^n},\]where $\cos \theta = \frac{1}{5}.$
train