Answer:
The depth of the reflector is 0.84 feet
Step-by-step explanation:
<em>(See the figure below)</em>
The equation of a parabola centered at the origin with an axis of symmetry on y-axis is:
(1)
With p the distance from the origin to the focus using p=6, the equation (1) of the parabola becomes:
(2)
Note that the point B is on the parabola, so this point should satisfy the parabola equation (2) that allow us to use the value x=4.5 to find the y value associated to it, that it is the depth (h) of the reflector:
, solving for y
<h3>Given</h3>
regular paper costs $3.79 per ream
recycled paper costs $5.49 per ream
$582.44 was spent for 116 reams
<h3>Find</h3>
the numbers of reams of each type that were purchased
<h3>Solution</h3>
Let r and g represent the numbers of reams of regular and recycled ("green") paper, respectively.
... r + g = 116 . . . . . . . . 116 reams were purchased
... 3.79r + 5.49g = 582.44 . . . . this is the total cost of the purchase
Solve the first equation for r and substitute that into the second equation.
... r = 116 - g
... 3.79(116 - g) + 5.49g = 582.44 . . . . . use the expression for r
... 1.70g + 439.64 = 582.44 . . . . . . . . . simplify
... g = (582.44 -439.64)/1.70 = 84 . . . . subtract the constant, divide by 1.70
... r = 116 -84 = 32 . . . . . . . . . . . . . . . . . use the equation for r
32 regular reams and 84 recycled reams were purchased
Now, we can just multiply it and obtain the result
I used law presented on this example
To solve this problem you must apply the proccedure shown below:
1. You have that 
varies jointly as 
and 
and inversely as the product of 
and 
. Therefore, you can write the following equation, where 
is the constant of proportionality:
2. Now, you must solve for the constant of proportionality, as following:
3. Susbtiute values:
4. Substitute the value of the constant of proportionality into the equation:
The answer is:
The person needs to leave it for 4 mores years to reach 22600 dollars. please give Brainliest :)
