
                <div class="practice">
                    <p><strong>Exercise:</strong> There is no unique parametrization for a contour $C.$
                        You should verify that
                        \begin{eqnarray*}
                        z(t)&amp;=&amp;e^{it} =\cos t+i\sin t,\; 0\leq t\leq 2\pi \\
                        z(t)&amp;=&amp; e^{2\pi it} =\cos \left(2 \pi t\right) +i \sin \left(2 \pi t\right),\; 0\leq t\leq 1\\
                        z(t)&amp;=&amp;e^{\pi/2 it} =\cos \left( \f