Question

Which of the equations below could be the equation of this parabola?

Answer 1

Answer:

Option B: $y = -\frac{1}{2} x^2$

Step-by-step explanation:

The parabola has its concavity downwards, so we need a function in the model:

$y = ax^2 + bx + c$

With a negative value of 'a'

The vertex is (0,0), so we have that:

$0 = 0a + 0b + c$

$c = 0$

The x-coordinate of the vertex is given by the equation:

$x\_vertex = -b/2a$

$-b/2a = 0$

$b = 0$

So we have a function in the model:

$y = ax^2$

With a < 0

The only option with this format is B:

$y = -\frac{1}{2} x^2$