Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
PLEASE HELP WITH MY TRIG HW: Parabolas *BEST ANSWER AWARDED*?
Please solve this for me. Best answer awarded!
5 Answers
- PinkgreenLv 73 years ago
Let the equation be
(y-2)^2=4a(x+5)
The focus is (1,2)=>
a=sqr[(1+5)^2+(2-2)^2]=>
a=6
=>
(y-2)^2=24(x+5)
or
y^2-24x-4y-116=0
is the required equation.
- DWReadLv 73 years ago
First determine the orientation of the parabola.
The vertex and focus are horizontally aligned (they have the same y-coordinate), so the parabola is horizontal.
The focus lies to the right of the vertex, so the parabola opens to the right.
Vertex-form equation for a right-opening parabola:
x = a(y-k)² + h
with
a > 0
vertex (h,k)
focal length p = 1/|4a|
focus (h+p,k)
Apply your data and solve for h, k, and a.
vertex (h,k) = (-5,2), so h = -5 and k = 2
focus (h+p,k) = (1,2)
h+p = 1
-5+p = 1
p = 6
a = 1/|4p| = 1/24
The equation becomes
x = (1/24)(y-2)² - 5
- ?Lv 73 years ago
axis of symmetry is parallel to the x-axis, it has an equation of (y - k)^2 = 4p (x - h), where the focus is (h + p, k)
focus (1,2) vertex (-5,2) ... h = -5, k = 2
. . . h+p = 1 .. p = 6
just fill in the equation ...
(y - k)^2 = 4p (x - h)
(y - 2)^2 = 24(x + 5)
- RealProLv 73 years ago
Focus and vertex lie on a horizontal line so the parabola will be horizontal, taking form
x-h = a(y-k)^2
Where (h,k) are coordinates of vertex.
The y term is squared as opposed to an "everyday" vertical parabola where the x term is squared.
Here a = 1/(4p) where p=6 is distance between focus and vertex.
Focus is to the right of the vertex so parabola opens right and a>0.
If the parabola opened left then we would have a = -1/(4p).
Put together
x+5 = (1/24)(y-2)^2
- How do you think about the answers? You can sign in to vote the answer.