What is the sum from n=1 to infinity of (cos(2))^n ?

The sum from n=1 to infinity of (cos(2))^n is 1/(1-cos(2))-1

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sum from n=1 to infinity of (cos(2))^n

n = 1 \sum \infty (cos (2))^{n}

\frac{1}{1 - cos ( 2 )} - 1

Decimal

- 0.29385 \dots

Solution steps

n = 1 \sum \infty (cos (2))^{n}

n = k \sum \infty (a_{n}) = n = 0 \sum \infty (a_{n}) - a_{0} - a_{1} - \dots a_{k - 1}

= n = 0 \sum \infty (cos (2))^{n} - (cos (2))^{0}

n = 0 \sum \infty (cos (2))^{n} = \frac{1}{1 - cos ( 2 )}

= \frac{1}{1 - cos ( 2 )} - (cos (2))^{0}

Simplify

= \frac{1}{1 - cos ( 2 )} - 1

What is the sum from n=1 to infinity of (cos(2))^n ?
The sum from n=1 to infinity of (cos(2))^n is 1/(1-cos(2))-1