The vertex of this parabola is at (-5, -2). When the x-value is -4, the
y value is 2. What is the coefficient of the squared expression in the
parabola's equation?
(-5,-2)
© A. 1
O B. -1
C. 5
D. 4

Respuesta :

Answer: D. 4

So you know the vertex is at (-5,-2) and there is a point (-4,2). This means you can write it in vertex form.


Vertex form is y= a(x-h)^2 +k
Therefore:
y= a(x+5)^2 -2

Now since you know that plug in the point to find a.

2 = a(-4+5)^2-2
4 = a

So your equation is:
y= 4(x+5)^2 -2

Now you want to know the coefficient of the squared expression. So let’s multiply it out.

y= 4 [(x+5)(x+5)]-2
y= 4(x^2+10x+25)-2
y= 4x^2+40x+100-2
y= 4x^2 + 40x + 98

Therefore your coefficient is 4.