Question

The sum of the series $1 + 1/2! + 1/4! + \dots \infty$ is:

• A. $e$
• B. $(e+e^{-1})/2$
• C. $(e-e^{-1})/2$
• D. $e^{2}$

Hint:

$(e+e^{-1})/2$ is the definition of the hyperbolic cosine function, $\cosh(1)$.

Answer 1

The Correct Option is B