Answer
(a) Focus: $F(-\frac{1}{8},0)$
Directrix: $x=\frac{1}{8}$
$Focal~diameter=\frac{1}{2}$
(b)
Work Step by Step
Equation of a parabola with horizontal axis: $y^2=4px$
$x=-2y^2$
$y^2=-\frac{1}{2}x$
$4p=-\frac{1}{2}$
$p=-\frac{1}{8}$
Focus: $F(p,0)=F(-\frac{1}{8},0)$
Directrix: $x=-p=\frac{1}{8}$
$Focal~diameter=|4p|=\frac{1}{2}$
