Question

Write the equation of the quadratic function with roots -9 and and -3 and a vertex at (-6, -1).

Answer 1

start with \(a(x+9)(x+3)\) and then solve for \(a\)

Answer 2

or start with \(f(x)=a(x+6)^2-1\) and solve for \(a\) either way.
you need the steps?

Answer 3

@Traxter ?

Answer 4

Ok, so you have y= a(x+9)(x+3) and you need to find a.
If we put in x=-6, y=-1 we get:
\[-1=a(3)(-3)\]
\[-1=-9a\]
\[a=\frac{1}{9}\]
So we have \[y=\frac{1}{9}(x+9)(x+3)\]

Answer 5

Please let me know if I can make anything more clear :)

Answer 6

so that would be the final answer?

Answer 7

or equation

Answer 8

@Traxter

Answer 9

\[y=\frac{1}{9}(x+9)(x+3)\]
Or you could expand it:
\[y=\frac{1}{9}(x^2+12x+27)\]
\[y=\frac{x^2}{9}+\frac{4}{3}x+3\]

Answer 10

You alright with that?

Answer 11

yes.thank you :)

Answer 12

No worries :)