linkte attıgım ıspata göre yaparsak;
$\dfrac{d^2y}{dx^2}=\dfrac{\dfrac{d}{d\theta}\left[\dfrac{dy}{dx}\right]}{\dfrac{dx}{d\theta}}$ 'i kullanıcağım
$------------------------$
$\dfrac{dy}{d\theta}=-[e^{-\theta}+tan^\theta+1]$
$\dfrac{dx}{d\theta}=e^\theta(tan^2\theta+tan\theta+1)$ olur
$------------------------$
$\dfrac{\dfrac{d}{d\theta}\left[\dfrac{-[e^{-\theta}+tan^\theta+1]}{e^\theta(tan^2\theta+tan\theta+1)}\right]}{e^\theta(tan^2\theta+tan\theta+1)}=\cdots$