\( \int \cos (x) \cdot e^{\sin (x)} d x \)
mit u=sin(x) hast du \( \frac{du}{dx} = u' = cos(x) \) und
damit \( dx = \frac{du}{cos(x)} \). Also
\( \int \cos (x) \cdot e^{\sin (x)} d x = \int \cos (x) \cdot e^{u} \frac{du}{cos(x)} = \int e^{u} du \)
\( = e^{u}+C = e^{sin(x)} + C\)