I found a conics problem in my book which has given me the equation of the directrix and the coordinates of the focus of a rightward opening parabola (open end towards the positive side of the $x$-axis) and has asked me to draw the conic section (parabola).
In the problem, the equation of the directrix is given as $x+y+1=0$, but isn't the directrix of a rightward opening parabola a vertical line parallel to the $y$-axis, and shouldn't it be in the form $x=c$?
You are correct, the directrix should be of the form $x=c$. There might be something else to the question. The parabola might have been rotated.