The error bars are used to indicate the variability of the data presented in a graph.
There are several quantities that can be used to generate error bars in the graph. These are:
standard deviation
standard error
confidence interval
Usually, one standard deviation above and below the mean is used although it is advised to indicate which variability data is used to generate the error bars in the graph since the 3 quantity given are not equal.
ANSWER

EXPLANATION
Since the parabola has the (0, 0) and the directrix at y=2.
The equation is of the form

where (h,k) is the vertex.
The vertex is half way between the directrix and the focus.
The vertex will be at (0,1)
and is the distance from the vertex to the focus which is 1.


Answer:
The answer is
<h2>

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Step-by-step explanation:
The distance between two points can be found by using the formula
<h3>

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where
(x1 , y1) and (x2 , y2) are the points
From the question the points are
(9,-8) and (-7,-5)
The distance between them is

We have the final answer as

Hope this helps you