Question

HELP ME!! im so stumped. will give brainliest!

Answer 1

Answer:

$x=1+\sqrt{3}$ and $x=1-\sqrt{3}$

Step-by-step explanation:

We have been given the parabola with vertex (1, -9) and y intercept at (0, -6).

Now we need to find the x-intercepts of that parabola. So first we begin by finding the equation of parabola using vertex formula:

$y=a\left(x-h\right)^2+k$

Vertex for this formula is given by (h,k)

Compare that with given vertex (1,-9), we get: h=1, k=-9

So plug these into vertex formula:

$y=a\left(x-1\right)^2-9$...(i)

Plug given point (0, -6). into (i)

$-6=a\left(0-1\right)^2-9$

$-6=a\left(-1\right)^2-9$

$-6=a\left(1\right)-9$

$-6+9=a$

$3=a$

Plug a=3 into (i)

$y=3\left(x-1\right)^2-9$

Now to find x-intercept, we just plug y=0 and solve for x

$y=3\left(x-1\right)^2-9$

$0=3\left(x-1\right)^2-9$

$9=3\left(x-1\right)^2$

$3=\left(x-1\right)^2$

$\pm \sqrt{3}=x-1$

$1+\pm \sqrt{3}=x$

Hence final answer are

$x=1+\sqrt{3}$ and $x=1-\sqrt{3}$