A page should have perimeter of 42 inches. The printing area within the page
would be determined by top and bottom margins of 1 inch from each side, and the
left and right margins of 1.5 inches from each side. What should be the overall
dimensions of the page in order to maximize the printing area?

Respuesta :

Overall  dimensions of the page in order to maximize the printing area is  page should be 11 inches wide and 10 inches long .

Step-by-step explanation:

We have , A page should have perimeter of 42 inches. The printing area within the page  would be determined by top and bottom margins of 1 inch from each side, and the  left and right margins of 1.5 inches from each side. let's assume  width of the page be x inches  and its length be y inches So,

Perimeter = 42 inches

[tex]2(x+y) = 42\\x+y = 21\\y = 21-x[/tex]

width of printed area = x-3  & length of printed area = y-2:

area = [tex]length(width)[/tex]

[tex]area = (x-3)(y-2)\\area = (x-3)(21-x-2)\\area = (x-3)(19-x)\\area = -x^{2} + 22x -57[/tex]

Let's find [tex]\frac{d(area)}{dx}[/tex]:

[tex]\frac{d(area)}{dx}[/tex] = [tex]\frac{d(-x^{2}+22x-57)}{dx} = -2x +22[/tex] , for area to be maximum [tex]\frac{d(area)}{dx}[/tex]= 0

⇒ [tex]-2x+22 = 0\\2x =22\\x=11 inches[/tex]

And ,

[tex]y = 21-x\\y = 21-11\\y = 10 inches[/tex]

Overall  dimensions of the page in order to maximize the printing area is  page should be 11 inches wide and 10 inches long .

So, the page should be 11 inches wide and 10 inches long

The perimeter of the rectangle:

It is the total distance covered by the rectangle around its outside.

Let the width of the page be [tex]x[/tex] inches

and its length be [tex]y[/tex] inches

Then we can write as,

[tex]2(x+y) = 42\\x+y = 21\\y = 21-x[/tex]

And the width of printed area =[tex]x-3[/tex]

length of printed area =[tex]y-2[/tex]

Then the area will be,

[tex](x-3)(y-2)= (x-3)(21-x - 2)\\= (x-3)(19-x)\\= -x^2 + 22x - 57[/tex]

Now, differentiating with respect to [tex]x[/tex]

[tex]\frac{dA}{dx} =-2x + 22\\=0\\2x=22\\x = 11[/tex]

Then [tex]y = 21-11 = 10[/tex]

The page should be 11 inches wide and 10 inches long

Learn more about the topic of the perimeter of the rectangle:

https://brainly.com/question/26584519