Answer:
Dimension - 16in by 16in by 32in
Volume - 8,192in³
Explanation:
Let the length and width of the rectangular package be x and y respectively. Since end of the package is a square, the perimeter of the package will be expressed as P = 4x+y and the volume will be expressed as V = x²y
If a postal service will accept a package if its length plus its girth is not more than 96 inches, then the perimeter is equivalent to 96 inches.
96 = 4x+y
y = 96-4x
Substituting the value of x into the formula for calculating the volume, we will have;
V(x) = x²(96-4x)
V(x) = 96x²-4x³
To get the dimensions and volume of the largest package, we will find V'(x) and equate it to zero.
V'(x) = 192x-12x²
192x-12x² = 0
Factoring out x;
x(192-12x) = 0
x = 0 and 192-12x = 0
12x = 192
x = 192/12
x = 16
This shows that we have a maximum value at x = 16 and minimum at x = 0
To get y, we will substitute x = 16 into the expression y = 96-4x
y = 96-4(16)
y = 96-64
y = 32
- The dimensions of the largest package is therefore 16in by 16in by 32in
- Volume of largest package = x²y = 16²*18 = 8,192in³