Question

Find the equation of the directrix of the parabola $y^2+4y+4x+2=0$

Answer 1

Given equation of parabola $y^2+4y+4x+2=0$

i.e; $(y+2{)}^2+4x+2=0$

$(y+2{)}^2=-4(x-\frac{1}{2})$

Its directrix is $x-\frac{1}{2}=1$

i.e; $x=1+\frac{1}{2}=\frac{3}{2}$