Answer:
x = 28 m
y = 14 m
A(max) = 392 m²
Step-by-step explanation:
Rectangular garden A (r ) = x * y
Let´s call x the side of the rectangle to be constructed with a rock wall, then only one x side of the rectangle will be fencing with wire.
the perimeter of the rectangle is p = 2*x + 2*y ( but in this particular case only one side x will be fencing with wire
56 = x + 2*y 56 - 2*y = x
A(r) = ( 56 - 2*y ) * y
A(y ) = 56*y - 2*y²
Tacking derivatives on both sides of the equation we get:
A´(y ) = 56 - 4 * y A´(y) = 0 56 - 4*y = 0 4*y = 56
y = 14 m
and x = 56 - 2*y = 56 - 28 = 28 m
Then dimensions of the garden:
x = 28 m
y = 14 m
A(max) = 392 m²
How do we know that the area we found is a local maximum??
We find the second derivative
A´´(y) = - 4 A´´(y) < 0 then the function A(y) has a local maximum at y = 14 m
You would pay 24 dollars and the box would be 24 cubic feet.
Because the account is compounded continuously, Euler number is required
e = 2.7182818
Answer:
that is the solution to the question
The answer is

. I've demonstrated the 'split and combine' method in the image attached.
This principal is based on the fact that you can multiply and divide radicals as you would with regular integers, but you remember that the answers remain as radicals unless the number you're dealing with is a square (e.g. 9, 16, 25).