Hi,

I am having trouble understanding a question:

I know the maclaurin series up to $\displaystyle x^4$ for cosh(x) goes

$\displaystyle \cosh(x) = 1 + \frac{x^2}{2} + \frac{x^4}{24}$

But what happens when it is $\displaystyle \cosh(x^2)$ my understanding of it makes me think that the outcome would be this:

$\displaystyle \cosh(x^2) = 1 + \frac{x^4}{24}$

Does anyone know if that is correct

Thanks for any help