Hello everyone!
can you please help me with this math activity? Help would be very appreciated.


The area of a rectangle is [tex]72^{2}[/tex]. State the dimensions of the rectangle with the least perimeter. Calculate the perimeter.

Respuesta :

Answer:

Dimensions are 6√2 by 6√2 and perimeter = 24√2.

Step-by-step explanation:

Let p by q gives the dimensions of the rectangle.

So, length = p and width is q.

Now, given that area of the rectangle is, A = pq = 72 ......... (1)

Now, P = 2(p + q) .......... (2) gives the perimeter of the rectangle.  

[tex]P = 2(\frac{72}{q} + q)[/tex] {From equation (1)}

Now, condition for perimeter to be maximum is  

[tex]\frac{dP}{dq} = 0 = 2(-\frac{72}{q^{2}} + 1 )[/tex]

⇒ q² = 72

q = 6√2

Therefore, from equation (1) [tex]p = \frac{72}{6\sqrt{2}} = 6\sqrt{2}[/tex].

So, the perimeter, P = 2(6√2 + 6√2) = 24√2. {From equation (2)}