Question

Which is the equation of the parabola?

coordinate plane with a parabola facing down with vertex at negative 3 comma 0, the point negative 3 comma negative 5 and a horizontal line going through 0 comma 5

y = −one twentieth(x − 3)2
y = −one twentieth(x + 3)2
y = one twentieth(x − 3)2
y = one twentieth(x + 3)2

Answer 1

• y = -1/20(x + 3)²

Explanation:

Consider the parent function:

• y = x²

The graph of the function open up and the vertex is at the origin, the point (0, 0)

Now, if it opens down, it means it is a reflection of the parent function over x axis, hence it has a negative coefficient, the function becomes:

• y = -x²

The vertex is shifted to the point (-3, 0). It means the function also translated left by 3 units, the function becomes:

• y = -(x + 3)²

Since all the options have 1/20 as a coefficient, our function is:

• y = -1/20(x + 3)²

This is option B