Question

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

y = -x^2 - 1
y = -(x - 1)^2
y = -(x + 1)^2

Answer 1

vertex form

for

y=a(x-h)^2+k
vertex is (h,k)
and if a is poisitve it opens up and if it is negative it opens down

so  it is opening down and has vertex at (-1,0)

y=-(x-(-1))^2+0
y=-(x+1)^2

last option

Answer 2

Answer:

C. $-(x+1)^2$

Step-by-step explanation:

We have been given that a parabola has a vertex at (-1, 0) and opens down. We are asked to find the equation of the parabola.

We know that the vertex form of parabola is in form: $a(x-h)^2+k$, where, point (h,k) is the vertex of parabola and sign of 'a' determines whether parabola opens upwards and downwards.

Since the vertex of our given parabola is at (-1,0) and it opens downwards, so the leading coefficient will be negative.

$-(x--1)^2+0$

$-(x+1)^2$

Therefore, the equation of the parabola is $-(x+1)^2$ and option C is the correct choice.