Answer:
(3, 0)
Step-by-step explanation:
A parabola is the locus of a point such that the distance from a fixed line called directrix and the distance from a fixed point called focus is constant.
The equation of a parabola with a vertex at (h, k) with axis of symmetry parallel to the y axis is given as:

The directrix is at y = k - p, and focus is at (h, k + p).
Given an equation -1/16(x-3)^2 + 4 = y, expressing it in standard form is:

Comparing with the standard form:
The center = (h, k) = (3, 4)
Also, -16 = 4p
p = -4
Directrix is at y = k - p = 4 - (-4) = 8
Directrix is at y = 8
The focus is at (h, k + p) = (3, 4 + (-4)) = (3, 0)
The focus is at (3, 0)
Angle of elevation is angle measured from horizontal line to line of sight, The distance from the plane to the observer is 25,636 feet approx
<h3>What is angle of elevation?</h3>
You look straight parallel to ground. But when you have to watch something high, then you take your sight up by moving your head up. The angle from horizontal line to the point where you stopped your head is called angle of elevation. See the figure where angle OPD is the angle when observer saw the plane. It is measured from the horizontal line OD.
Refer to the attached figure.
It is given that we have
Length of PD = |PD| = 21,000 feet
Angle ∠OPD = 55°
Assuming length of OP = |OP| = x feet, we get the sin ratio as

(tan 55° was calculated from online calculator)
Thus,
The distance from the plane to the observer is 25,636 feet approx.
Learn more about trigonometric ratios here:
brainly.com/question/22599614
Answer:
64 pies sold
Step-by-step explanation:
x = number of cakes sold
y = number of pies sold
Last weekend the bakery sold 118 total items
x + y = 118
Last weekend the bakery earned $1,932.
18x + 15y = 1,932.
Get rid of one of the terms, in this case x.
x + y = 118 becomes
18x + 18y = 2124
Subtract the equations from each other
(18x - 18x) + (18y - 15y) = 2124 - 1932
3y = 192
y = 64
Subsititue y into the orginal qeuation to solve for x and check it's right.
x + 64 = 118
x = 118 - 64 = 54
18(54) + 15(64) = 1932