Hello, everyone. I’m trying to solve numerically the following integral:

\int _{-\infty} ^{\infty} \exp(-z^2/2)\ln(2\cosh(z)) dz = 2.67636.

For that, I write the following

```
using QuadGK
f3(z) = exp(-z^2/2)*log(2*cosh(z))
V = quadgk(f3,-Inf,Inf)
```

but I receive the following error message

```
DomainError with -0.9375:
integrand produced NaN in the interval (-1.0, -0.875)
```

I’m not being able to understand why I receive this, since the integral converge. Can anyone help?