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Section 2.1
Question 73
For this question, I seek a hint for parts a & b.
Question 73
For this question, I seek a hint for parts a & b.
a hint for parts a : the length of corrals is 2x, the width is y
fencing or perimeter=200ft
& b: to determine the maximum first find x and y
a hint for parts a : the length of corrals is 2x, the width is y
fencing or perimeter=200ft
& b: to determine the maximum first find x and y
correct
correct
in part a
200 = 2(2x) + 2y
I gave you bad hint, a hint for part a : the perimeter=200ft includes the fence in the middle, the shared fence
so you have perimeter
Let x represent the dimension perpendicular to the shared fence. (these 2x)
Then the dimension parallel to the shared fence will be: (3y)
3y = 200-2x
y = (200-2x)/3
y = (2/3)(100-x)
The area will be the product of these dimensions, so will be:
area = x*y
area = x(2/3)(100-x)
area = (2/3)(100x -x^2)
area = (-2/3)(x^2 -100x)
To complete the square, we need to add the square of half the x-coefficient inside parentheses, and the opposite of that quantity outside parentheses.
area = (-2/3)(x^2 -100x+50^2)-(-2/3)50^2. . . . complete the square
area = (-2/3)(x -50)^2 +5000/3
The vertex of this parabolic curve is at x=50, so the dimensions of the maximum area is at x = 50
then substitute it in
y = (200 -2*x)/3
y = (200 -2*50)/3
y=100/3
y= 33 &1/3 feet
I just don't know why question was to express the area in terms of x when there is much faster and easier way to get same answer
given perimeter 200ft
half of it is 2 times the length 2x=>means 2*2x=100=>the length 2x=50ft
half of it is 3 times the width 3y=>means 3y=100=>the width y=100/3 =33&1/3ft=33.33ft
then area=2x*y=50ft*33.33ft=1666.5ft^2