What is the equation of the parabola with a directrix at y = -4 and focus (0, 4)?
1 answer:
Answer:
Step-by-step explanation:
We are given the directrix equation and the location of the focus as a means to determine what the vertex (h, k) of the parabola is. Since the directrix is a horizontal line AND since the directrix is below the focus, AND since the parabola ALWAYS wraps itself around the focus, this is a positive parabola of the form
We also know that since the vertex is directly in between the focus and the directrix, it has coordinates of (0, 0). So h = 0 and k = 0.
By definition, p is the distance between the vertex and the focus (and also the vertex and the directrix since they are both the same). Therefore, p = 4.
Filling in our equation with those values gives us
and solving for y gives us
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Answer:
A person should work 32 hours to earn $384
Step-by-step explanation:
A worker's earring E are a function of the number of hour, H at a rate of 12/hr.
We need to write the function.
The function will be:
Earning is represented by E and Hour is represented by H
Now, How many hours would a person have to work to earn 384
We are given E=384, we need to find H
Putting values in above function and finding hours H
So, A person should work 32 hours to earn $384