d / t \
--\(E *cos(t), x)/
dx
$$\frac{\partial}{\partial x} \left( e^{t} \cos{\left(t \right)}, \ x\right)$$
2
d / t \
---\(E *cos(t), x)/
2
dx
$$\frac{\partial^{2}}{\partial x^{2}} \left( e^{t} \cos{\left(t \right)}, \ x\right)$$
3
d / t \
---\(E *cos(t), x)/
3
dx
$$\frac{\partial^{3}}{\partial x^{3}} \left( e^{t} \cos{\left(t \right)}, \ x\right)$$