Write the equation of the parabola with a focus at (-3, -5) and a directrix at y = -7.

Mathematics

1 answer:

lilavasa [31]3 years ago

3 0

Answer:

The directrix is negative so the equation will be

x^2=4ay

x=-3

y=-5

a=x^2/4y

a=(-3)^2 /4*(-5)

a=9/20

x^2=4*(9/20)*y

x^2=9/5y

Step-by-step explanation:

The directrix always determine the equation to use. It is also important to notice the sign(-+).

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10x.

Step-by-step explanation:

It is given that,

JK = 3x

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Let as consider the line as shown in the below figure.

From the figure it is clear that,

$JK+KL+LM=JM$

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Emma is standing 10 feet away from the base of a tree and tries to measure the angle of elevation to the top. She is unable to g

Vaselesa [24]

The complete question in the attached figure

step 1
find the tree height for an angle of elevation of 55°
tan 55°=opposite side angle 55°/adjacent side angle 55°
opposite side angle 55°=the tree height h1
adjacent side angle 55°=10 ft
so
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step 2
find the tree height for an angle of elevation of 75°
tan 75°=opposite side angle 75°/adjacent side angle 75°
opposite side angle 75°=the tree height h2
adjacent side angle 75°=10 ft
so
tan 75°=h2/10-------> h2=10*tan 75°-----> h2=37.32 ft

therefore

the height of the tree is within the range [14.26,37.32]

Part 1) 4.2 ft

the value is not in the interval [14.26,37.32]
therefore
it is Not Reasonable

Part 2) 14.7 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 3) 24.4 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 4) 33.9 ft

the value is in the interval [14.26,37.32]
therefore
it is Reasonable

Part 5) 39.1ft

the value is not in the interval [14.26,37.32]
therefore
it is Not Reasonable

Part 6) 58.7 ft

the value is not in the interval [14.26,37.32]
therefore
it is Not Reasonable