If $A=\left\{z=x+iy/\mathrm{real} \mathrm{part} \mathrm{of} \frac{\overline{z}-1}{z-i}=2\right\}$ then the locus of the point $P\left(x,y\right)$ in the Cartesian plane is

If $e^{ix}$ is a solution of the equation $z^n+p_1{z}^{n-1}+p_2{z}^{n-2}+\dots \dots +p_n=0$, where $p_i$ are real $\left(i=1,2,3,\dots \dots \dots n\right)$,then

$p_n\sin nx+p_{n-1}\sin \left(n-1\right)x+\dots +p_1\sin x+1=$