Find the parameterization: The left half of the parabola $y=x^2+2x$

Question

Find the parameterization: The left half of $y=x^2+2x$

Here's what I did:

I set $x=t$, so that $y=t^2+2t$

Then the parameterization would be:
$$x=t$$ $$y=t^2+2t$$ $$t<0$$

Is that right?
If it is, can the restriction be $t \le 0$ or does it have to be $t<0$?

Answer 1

I guess the left side of your parabola it means to the left of the axis of symmetry which is the line $x=-1$ so you can put $$t\le -1$$ instead of $t\le 0$.