Material=wall+2*side and material is 40 ft so:
40=w+2s
w=40-2s
Area=ws, using w from above we get:
A=(40-2s)s
A=40s-2s^2
dA/ds=40-4s and d2A/ds2=-4
Since d2A/ds2 is a constant negative acceleration, when dA/ds=0, A(s) is at an absolute maximum.
dA/ds=0 when 4s=40, s=10 ft
And since w=40-2s, w=20 ft
So the dimensions of the pen are 20 ft by 10 ft, with the 20 ft side being opposite the wall. And the maximum possible area is thus 200 ft^2
Easily we can use formula y=(x-h)^2 +k
as equation of a parabola if vertex was (h,k):
Y=(x-1)^2 + 3
and maybe node (2,6) is incorrect for this vertex of a parabola!!!
X= 1/2 or x = 3/2.
Step 1: factor left side of equation. (2x-1)(2x-3)=O
Step 2: Set factors equal to 0. 2x-1=0 or 2x-3=0
X= 1/2 or x = 3/2.
Answer:
the first on 5×107=535 the second one 3×105=315
