A negative sequence relay is commonly used to protect

A three–bus network is shown in the figure below indicating the p.u. impedances of each element

The bus admittance matrix, $$Y$$-$$bus,$$ of the network is

A point Z has been plotted in the complex plane, as shown in figure below. The plot of the complex number $$y=\frac1z$$ is

Given two continuous time signals $$x\left(t\right)=e^{-t}$$ and $$y\left(t\right)=e^{-2t}$$ which exist for t > 0, the convolution z(t) = x(t)*y(t) is