Can someone help me please. I'm desperate I can get halfway through but I can't figure it out 100%..

Find the x-intercepts of the parabola with vertex (4,-1) and y-intercept (0,15). Answer in this form: (x1,y1),(x2,y2)

Question

Can someone help me please. I'm desperate  I can get halfway through but I can't figure it out 100%..

Find the x-intercepts of the parabola with vertex (4,-1) and y-intercept (0,15). Answer in this form: (x1,y1),(x2,y2)

anonymous · Answer

vertex is $(4,-1)$ so you know it looks like 
$$y=a(x-4)^2-1$$ and we can solve for $a$ because we know that if $x=0$ then  $y=15$ so set 
$$15=a(0-4)^2-1$$
$$15=16a-1$$
$$16a=16$$
$$a=1$$

anonymous · Answer

so your parabola has the equation 
$$y=(x-4)^2-1$$ now you can set it equal to zero and solve

anonymous · Answer

$$(x-4)^2-1=0$$
$$(x-4)^2=1$$
$$x-4=1$$ or 
$$x-4=-1$$

$$x=5$$ or $$x=3$$

anonymous · Answer

Trying it right now

anonymous · Answer

OH MY GOODNESS THANK YOU SO MUCH! <3