Equation of the directrix of the parabola  $y^2+4y+4x+2=0$ is 

Given equation can be written as 

$(y+2{)}^2=-4x+2=-4(x-1/2)$ 

which is of the form $Y^2=4aX$

where $Y=y+2,X=x-1/2,a=-1$ 

The directrix of the parabola $Y^2=4aX$ is $X=-a$

$\Rightarrow x-1/2=-(-1)\Rightarrow x=3/2$ is the equation of the directrix of the given parabola