I'm trying to sketch a parabola before even finding the range of it. For some reason I've never known how to do this, whether I was away or not, I'm not sure.
So I have, $y=-x^2-2x$. I'd usually find $x$/$y$-intercepts and then the $x$-intercepts are always $2$ values in which both parts of the parabola pass through. So, I substituted $y = 0$ in to the original equation to find the $x$ values, and I'm not sure how to solve $-x^2-2x$.
Any help would be much appreciated and if possible a small walk-through for sketching parabolas based on the equation (note: I only struggle with equations that have $2-3$ terms, I'm fine with $1$).