Cara has $25 to buy dry pet food a pound of dog food costs $2 and treats are $1 apiece if she buys 9 pounds of food the greatest
1 answer:
You might be interested in
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
For this case we have the following functions:
By definition of composition of functions we have:
Then substituting:
So:
Answer: