Using the chain rule, we have:
\begin{align*}
\frac{\partial x}{\partial s} &= \cos(s+t), \\
\frac{\partial y}{\partial s} &= -\sin(s+t), \\
\frac{\partial z}{\partial s} &= 0, \\
\frac{\partial x}{\partial t} &= \cos(s+t), \\
\frac{\partial y}{\partial t} &=
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