You have 332 feet of fencing to enclose a rectangular region. What is
the maximum area?

A. 6889 square feet


B. 6885 square feet


C. 110,224 square feet


D. 27,556 square feet

Respuesta :

6889 square feet
Letter A

Answer:

Option A is correct

The maximum area is, 6889 square feet

Step-by-step explanation:

Perimeter of a rectangle is given by:

[tex]P = 2(l+w)[/tex]

where,

l is the length and w is the width of the rectangle respectively.

As per the statement:

You have 332 feet of fencing to enclose a rectangular region.

⇒[tex]P = 332[/tex] feet

Then using perimeter formula:

[tex]332 =2(l+w)[/tex]

Divide both side by 2 we get;

[tex]166 = l+w[/tex]                

or

[tex]l=166-w[/tex]                  .....[1]

Area of a rectangle(A) is given by:

[tex]A = lw[/tex]                     .....[2]

Substitute the value of [1] in [2] we have;

[tex]A = (166-w)w[/tex]

⇒[tex]A = 166w -w^2[/tex]

We have to find the maximum area:

A quadratic equation [tex]y=ax^2+bx+c[/tex] then the axis of symmetry is given by:

[tex]x = -\frac{b}{2a}[/tex]

The maximum  area occurs at:

[tex]w = -\frac{166}{2(-1)} = \frac{166}{2} = 83[/tex] feet

Substitute the value of w in [1] we have;

[tex]l = 166-83 = 83[/tex] feet

Substitute the value of l and w in [2] we have;

[tex]A_{max} = 83 \cdot 83 = 6889[/tex] square feet

therefore, the maximum area is, 6889 square feet

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