Find the equation of the parabola with directrix x + 1 = 0 and y = 1, and the length of the latus rectum is 4. Sketch the graph.

1. 👍 0
2. 👎 0
3. 👁 118
1. x+1 = 0
X = -1 = h = axis.

F(-1,Y2)
V(-1,k)
D(-1,1)

1/a = 4 = Latus rectum
a = 1/4

1/4a = 1/1 = 1

k = y+1/4a = 1 + 1 = 2.

Y2 = k+1/4a = 2 + 1 = 3.

Y = a(x-h)^2 + k
Y = 1/4(x+1)^2 + 2

Use the following points for graphing:
(x,y)
(-3,3)
(-2,9/4)
V(-1,2)
(0,9/4)
(1,3)

1. 👍 0
2. 👎 0
posted by Henry

## Similar Questions

1. ### MATH! Urgent

umm suppose a parabola has a vertex at (0,2) and points (1,1) how would I derive the equation and focus, i've been trying to understand this for so long, I can't get it. Does this parabola have the equation (y-2)^2 = x and a focus

asked by sally on November 2, 2006
2. ### 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

asked by samantha on June 15, 2008
3. ### maths

Given that the equation of the parabola is 5y^2 + 24x = 0. Find (1)The Axis and vertex of the parabola (ii)The focus and the directrix (iii)The distance from the directrix to the focus

asked by mary on February 27, 2012
4. ### Geometry

Can someone please help me with these? 1. What are the focus and directrix of the parabola with the equation y=1/12 xsquared 2. what is an equation of a parabola with a vertex at the origin and directrix y=19/4 3. What are the

asked by Anonymous on May 28, 2019
5. ### Algebra2

Write an equation of a parabola with a vertex at the origin and a directrix at y=-5. my answer is focus 6,0, directrix =-6

asked by Steve on March 8, 2017
6. ### precallcuslus

can you check my work and explain the last question because I do not uderstand. Explain what each of the following represents, and how y = a(x - h)2 + k, a ≠ 0 and (x - h)2 = 4p(y - k), p ≠ 0 are equivalent. The equation (x -

asked by Anonymous on December 5, 2016
7. ### algebra 2

Directions: The focus and directrix of a parabola are given. Write an equation for each parabola. (2,4) y = 6 May you explain the procedures on how to solve this equation? Please be detailed on each step.

asked by meg on April 2, 2008
8. ### Math

determine vertex, focus and directrix of parabola. then graph the parabola. first equation: y^2 -2x-8=0 second equation: y^2 -4y -12x= 8 please show your work!

asked by doug on May 18, 2008
9. ### math

determine vertex, focus and directrix of parabola. then graph the parabola. first equation: y^2 -2x-8=0 second equation: y^2 -4y -12x= 8

asked by doug on May 18, 2008
10. ### 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? (5 points) A) 3x^2 + y^2 + 12x - 7 = 0 B) 3x^2 + 3y^2 + 12x - 7 = 0 C) 3x^2 + y + 12x - 7 =

asked by Mecie on April 16, 2012
11. ### precalculus

Find the focus, directrix, and focal diameter of the parabola. x = −4y2 I answered everything right except the directrix. which my ans was -1/16.

asked by amaa on December 1, 2012

More Similar Questions