
9.4.20 Curvilinear integrals
(a)
Problem:
Calculate the line integral of the \( 1^{\text {st }} \) kind along a space curve:
\[
\begin{array}{l}
\int_{\Gamma} z d l, \quad \text { where } \Gamma \text { is the arc of a conical helix: } \\
\left\{\begin{array}{c}
x=t \cos t \\
y=t \sin t, \\
z=t
\end{array}\right.
\end{array}
\]