# precal help

posted by .

Find a Parabola with Vertex (3,1) Focus (4,1)

Find the vertex of 4y^2+4y-16x+13=0

Find the center of an ellipse 9x^2+4y^2-36x-24y-36=0

Find an ellipse with minor axis of 8 and vertices at (-9,3),(7,3)

• precal help -

In all of these problems complete the square, then look at standard form of conic section.
For example to find the center of the ellipse
Find the center of an ellipse 9x^2+4y^2-36x-24y-36=0
9 x^2 -36 x -36 = -4 y^2 + 24 y

(-9/4) x^2 + 9 x + 9 = y^2 -6 y
(-9/4) x^2 + 9 x + 18 = y^2 -6 y + 9
(-9/4) x^2 + 9 x + 18 = (y-3)^2
x^2 - 4 x - 8 = (-4/9) (y-3)^2
x^2 - 4 x = (-4/9) (y-3)^2 + 8

x^2 - 4 x + 2 = (-4/9) (y-3)^2 + 10
(x-2)^2 + (4/9) (y-3)^2 = 10
You can see right now that center is at (2,3)
(x-2)^2/10 + (y-3)^2/(90/4) = 1

• error -

x^2 - 4 x = (-4/9) (y-3)^2 + 8

x^2 - 4 x + 4 = (-4/9) (y-3)^2 + 12
(x-2)^2 + (4/9) (y-3)^2 = 12
You can see right now that center is at (2,3)
(x-2)^2/12 + (y-3)^2/(27) = 1

## Similar Questions

1. ### Pre-Cal

Find the standard form of the equation of the ellipse. (Remember center is midpoint between either foci or vertices) (1) 9x^2+4y^2+36x-24y+36=0 (2) Vertices: (0,5)(0,-5) Passes through the point (4,2) Centered at the origin
2. ### Pre Cal.

1. Identify the conic section represented by: 9y^2+4x^2 - 108y+24x= -144?
3. ### algebra

I would like to have some help on this problem please. I'm so post to find the vertex and axis of the parabola.Does anyone have an idea?
4. ### PRECAL

Find a Parabola with Vertex (3,1) Focus (4,1) Find the vertex of 4y^2+4y-16x+13=0 Find the center of an ellipse 9x^2+4y^2-36x-24y-36=0 Find an ellipse with minor axis of 8 and vertices at (-9,3),(7,3)
5. ### pre cal

What is the center of the conic whose equation is x^2 + 2y^2 - 6x + 8y = 0 2.Which one of the following equations represents a hyperbola?
6. ### precal

complete the square to identify what type of conic you have, identify the key parts indicated and then graph conic. parabola: vertex,focus, directrix, focal diameter. ellipse: center,vertices, foci, eccentricity. hyperbola: center, …
7. ### math

let equation of an ellipse be x^2+4y^2+6x-8y+9=0 a. Find the standard form of the ellipse b. Find the center c. Find the vertices d. Find the foci e. Find the eccentricity
8. ### Precalculus(Please check and help)

Find the Equation. Please check the answers and help. Thanks! 1.) Ellipse with center (0,0), foci on x-axis; x intercepts; major axis of length 12, minor acis of length 8. I got : x^2/144 + y^2/64 = 1 2.) A parabola with vertex (0, …
9. ### Algebra

An engineer designs a satellite dish with a parabolic cross section. The dish is 14 ft wide at the​ opening, and the focus is placed 4 ft from the vertex. ​a) Position a coordinate system with the origin at the vertex and the​ …
10. ### Algebra

An engineer designs a satellite dish with a parabolic cross section. The dish is 10 ft wide at the​ opening, and the focus is placed 8 ft from the vertex. ​a) Position a coordinate system with the origin at the vertex and the​ …

More Similar Questions