coolbuggurl
contestada

Please help!!! I am stuck on this problem. Find the equation of the parabola given that the vertex is (-2,-20) and the y-intercept is (0,-12). The part where I input the answer is written as _x^2 + _x + _. However, for the last term I keep getting -12 but the last term is positive in the answer choice. I've used both equations of y-k = a(x-h)^2 and also the equation y=ax^2+bx+c.

Respuesta :

apologiabiology
easy

ok, so

for y=a(x-h)^2+k
the vertex is (h,k)
given that the the vertex is (-2,-20)
y=a(x-(-2))^2+(-20)
y=a(x+2)^2-20
find a
when x=0, then y=-12
-12=a(0+2)^2-20
-12=a(2)^2-20
8=4a
2=a

equation is
y=2(x+2)^2-20
if the last term is positive, then maybe y=2(x+2)^2+(-20)?
unless you typed something wrong, then you are right that the last term is -20