A parabola has a vertex at (-1, 0) and opens down. What is the equation of the parabola?

y = -x2 - 1

y = -(x - 1)2

y = -(x + 1)2

Question

A parabola has a vertex at (-1, 0) and opens down. What is the equation of the parabola?



y = -x2 - 1

y = -(x - 1)2

y = -(x + 1)2

imstuck · Answer

because it opens downward, it will have a negative in front of the parentheses with the x.  The x coordinate for the parabola is -1, but in standard form it must fit into the (x-___) format so it is (x-(-1)) which puts your center at (x+1).  The 0 in the y place means that the y coordinate has not moved from the origin.  So your equation for that parabola you wrote is choice three  y= -(x+1)^2