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

y = -(x + 1) 2

Explanation:

I don't have a step-by-step explanation I'm very sorry. But this is the correct answer!

Answer 2

The parent function
f(x) = x²
opens up and has its vertex at (0, 0).
When it is reflected across the x-axis, it opens down and its equation becomes
g(x) = -f(x) = -x²

When the vertex is translated 1 unit to the left, to (-1, 0), the function becomes
g(x) = -f(x+1) = -(x+1)²

Your best choice is ...
y = -(x + 1)²