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Find an equation of the parabola with vertex (-1, -5) and directrix x=-7.

Plz help need to pass this class right now before it’s to late

User Raduken
by
6.3k points

2 Answers

2 votes

Answer:

(y + 5)² = 24(x + 1)

Explanation:

(x - h)² = 4p(y - k)

(h,k) = (-1,-5)

p = -1 - (-7) = 6

4p = 4(6) = 24

Equation

(y - -5)² = 24(x - -1)

(y + 5)² = 24(x + 1)

User John Pitts
by
5.9k points
7 votes

Answer:

Base on the vertex (h, k) and the distance p between vertex and directrix, the standard form of parabola is written as:

(x – h)^2 = 4*p(y – k)

We have (-1, -5) as vertex.

=> (x + 1)^2 = 4*p(y + 5)

Now, we find p:

The distance between (-1, -5) and x = -7 is calculated by:

|-1 -(-7)| = |6| = 6

=> (x + 1)^2 = 4*6(y + 5)

=> (x + 1)^2 = 24(y + 5)

Hope this helps!

:)

User Emme
by
6.2k points