Pre-Calc

posted by .

for the conic y=5x^2-40x+78 find an equation in standard form and its vertex, focus, and directrix

  • Pre-Calc -

    complete the square
    y = 5(x^2 - 8x + ....) + 78
    = 5(x^2 - 8x + 16 - 16) + 78
    = 5( (x-4)^2 - 16) + 78
    = 5(x-4)^2 - 80 + 78
    = 5(x-4)^2 - 2

    take over ....

  • Pre-Calc -

    What's my next step??

  • Pre-Calc -

    We could write our answer in the form
    y+2 = 5(x-4)^2

    take a look at
    http://jwilson.coe.uga.edu/emt725/class/sarfaty/emt669/instructionalunit/parabolas/parabolas.html
    half-way down the page at example 3
    and follow the steps.

  • Pre-Calc -

    thank you!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Conic Sections

    How do you find the equation for this problem?
  2. Pre Cal

    write the equations of the parabola, the directrix, and the axis of symmetry. vertex: (-4,2) focus: (-4,6) if someone could explain how to do this problem then that would be great! thanks in advance! Formats to help you find the equation …
  3. pre cal

    find the standard form of the equation of a parabola with the vertex (0,0) and the directrix y=6 find the standard form of the equation of the ellipse with center (0,0) and foci at (+- 4square root 3, 0) and verticies (+-8,0)
  4. algebra

    6. Find the equation of each parabola described below. a) parabola with vertex (0,0) and the focus (0,7) b) parabola with focus (-3,0) and directrix x=3 c) parabola with vertex (3,3) and directrix x=-1 d) parabola with focus (-2,-1) …
  5. Math

    Find the vertex, focus, and directrix of the parabola. x^2 - 2x + 8y + 9 = 0 x^2 - 2x +1 = -8y + 9+ 1 (x-1)^2 = -8(y-1.25) vertex:(1,1.25) focus:(1,-.75) directrix: y=3.25 My teacher said that I have sign errors. I do not know where …
  6. Pre-cal

    Sketech the graph of the equation y^2+4y+2x+10=0. Identify the vertex, the focus and the equation for the directrix. Use the completing the square to put the equation into standard form as your first step. This is what I did. y^2 + …
  7. Pre-Calc

    Find the vertex, value of p, axis of symmetry, focus, and directrix for x – 4 = (-1/6)(y + 2)^2
  8. 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?
  9. Math Help

    With the given information below, write the standard form equation for the parabola. 1.) Vertex: (-1,2) Focus(-1,0) 2.) Vertex: (-2,1) Directrix x=1
  10. Math

    Using the following information for the Vertex and Directrix, write the standard form equation for the parabola with what is given below. Vertex: (-2,1) Directrix: x=1

More Similar Questions