Posted by Marie on Wednesday, March 7, 2007 at 9:14pm.
write the equations of the parabola, the directrix, and the axis of symmetry.
if someone could explain how to do this problem then that would be great! thanks in advance!
Formats to help you find the equation for a parabola:
(x - h)^2 = 4p(y - k)
Vertex = (h, k)
Focus = (h, k + p)
Directrix: y = k - p
You are given the vertex (-4,2) and the focus (-4,6).
Since we know k, which is 2, we can figure out p. Format = (h, k + p) for focus. Therefore, p = 4.
I'll set this up and let you take it from there:
[x - (-4)]^2 = 4(4)(y - 2)
The axis of symmetry is: x = -4 (vertex x-value).
I hope this will help.
good post. mathguru, if you would like to join us here at jiskha as a volunteer teacher, email me at
it did. thanks so much!
Thanks Bob! Just happy to help. :)
- Pre Cal - Anonymous, Wednesday, April 27, 2016 at 10:57pm
Answer This Question
More Related Questions
- Pre Cal Check - focus: (0,p) vertex: if not given, then it is assumed (0,0) ...
- pre cal - What is the center of the conic whose equation is x^2 + 2y^2 - 6x + ...
- algebra - 6. Find the equation of each parabola described below. a) parabola ...
- math - write an equation for the parabola with focus (1,3) and vetex (0,3) See ...
- algebra - Can someone check my answers please and if Im wrong please explain. 1...
- maths - Given that the equation of the parabola is 5y^2 + 24x = 0. Find (1)The ...
- Pre Cal. - 1. Identify the conic section represented by: 9y^2+4x^2 - 108y+24x= -...
- Pre-Calc - Find the vertex, value of p, axis of symmetry, focus, and directrix ...
- Algebra II - Write an equation for the parabola with focus (1,3) and vertex (0,3...
- Pre-cal - Sketech the graph of the equation y^2+4y+2x+10=0. Identify the vertex...