53.9k views
3 votes
The vertex of a parabola is (-2, -20), and its y-intercept is (0, -12).

The equation of the parabola is y =
x2 +
x +

1 Answer

6 votes

Answer:


y=2x^2+8x-12

Step-by-step explanation:

To write the quadratic equation, begin by writing it in vertex form


y = a(x-h)^2+k

Where (h,k) is the vertex of the parabola.

Here the vertex is (-2,-20). Substitute and write:


y=a(x--2)^2+-20\\y=a(x+2)^2-20

To find a, substitute one point (x,y) from the parabola into the equation and solve for a. Plug in (0,-12) the y-intercept of the parabola.


-12=a((0)+2)^2-20\\-12=a(2)^2-20\\-12=4a-20\\8=4a\\2=a

The vertex form of the equation is
y=2(x+2)^2-20.

You can convert this into standard form by using the distributive property.


y=2(x+2)^2-20\\y=2(x^2+4x+4)-20\\y=2x^2+8x+8-20\\y=2x^2+8x-12



User Nkvnkv
by
8.8k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories