Question

Alex has 20m barb wire to fence a rectangular lot. What are the dimensions of the lot that will contain the maximum area?

Answer 1

Are you supposed to use calculus?

Answer 2

yes..

Answer 3

\[
20=2x+2y \implies y=\frac{20-2x}{2}
\]

Answer 4

\[
A = xy = x(10-x)
\]

Answer 5

Minimize the function.

Answer 6

so sir, the answer is ?

Answer 7

Hell no.

Answer 8

I did the algebra, sir. You do the Calculus.

Answer 9

What is \(dA/dx\)?

Answer 10

integration ..

Answer 11

Differentiation.

Answer 12

differential calculus

Answer 13

\[
A = x(10-x)
\]

Answer 14

Find \(A'\)

Answer 15

thank u sir.

Answer 16

lol use differential !

Answer 17

You need \(A'=0\) to find critical points.

Answer 18

Based on the analysis of @wio
\[y=10-x\]
\[xy=10x-x\]
\[x(10-x)=10x-x\]
\[x^2-x=0 \rightarrow the final function\]

Answer 19

Well it is \[
10x-x^2
\]And \[
A'=10-2x = 0 \implies x= 5
\]