$$ \Phi(x)=\frac{1}{\sqrt{ 2\pi }}\int_{-\infty}^{x} e^{-t^{2}/2} , \mathrm{d}t $$
$$ \varphi(x)=\frac{1}{\sqrt{ 2\pi }}e^{-x^{2}/2} $$
$$ \Phi(x)=\frac{1}{\sqrt{ 2\pi }}\int_{-\infty}^{x} e^{-t^{2}/2} , \mathrm{d}t $$
$$ \varphi(x)=\frac{1}{\sqrt{ 2\pi }}e^{-x^{2}/2} $$