Question

A homeowner wants to fence a rectangular garden using 60ft. of fencing. An existing stone wall will be used as one side of the rectangle. Find the dimensions for which the area is maximum

Answer 1

so we will have 3 sides, 2w+l=60 would be the perimeter
and l*w = A
so l = 60-2w plug this into A
A = (60-2w)*w = -2w^2+60w
differentiate A with respect to W
-4w+60
set equal to 0
-4w+60 = 0
w = 15
which gives L = 60-2*15 = 30
w = 15, l = 30

Answer 2

we know this is a max because our function was a downward opening parabola.

Answer 3

understand?

Answer 4

yesss thank you very much i really apreciate it :)

Answer 5

np