Question 1184284


The equation {{{y^2+4x+ 4y +k=0 }}}represents a parabola whose latus rectum is:


{{{y^2+4x+ 4y +k=0}}}

{{{(y^2+ 4y) +4x+k=0}}}

{{{(y^2+ 4y+b^2)-b^2 +4x+k=0}}} ...........{{{b=2}}}

{{{(y^2+ 4y+2^2)-2^2 +4x+k=0}}}

{{{(y+2)^2-4 +4x+k=0}}}

{{{(y+2)^2=-4x+4-k}}}

{{{(y+2)^2=-4(x-1+k/4)}}}
 
 Latus rectum ={{{4}}} units


answer: D: {{{4}}}