Answer: A. A=(1000-2w)*w B. 250 feet
C. 125 000 square feet
Step-by-step explanation:
The area of rectangular is A=l*w (1)
From another hand the length of the fence is 2*w+l=1000 (2)
L is not multiplied by 2, because the opposite side of the l is the barn,- we don't need in fence on that side.
Express l from (2):
l=1000-2w
Substitude l in (1) by 1000-2w
A=(1000-2w)*w (3) ( Part A. is done !)
Part B.
To find the width w (Wmax) that corresponds to max of area A we have to dind the roots of equation (1000-2w)w=0 ( we get it from (3))
w1=0 1000-2*w2=0
w2=500
Wmax= (w1+w2)/2=(0+500)/2=250 feet
The width that maximize area A is Wmax=250 feet
Part C. Using (3) and the value of Wmax=250 we can write the following:
A(Wmax)=250*(1000-2*250)=250*500=125 000 square feets
-6.5 which in your answer choices is a
I'll use subscript notation for brevity, i.e.
.
By the chain rule,



We have

and

When
, we have

and the partial derivatives take on values of

So we end up with

15,640 * 7.2% = 1,126.80 Sales tax
Total cost:
cost of an item: 15,640 - 2,500 = 13,140.00
sales tax 1,126.80
registration fee <u> 106.00</u>
14,372.80 2nd option.
13. you need a total of 14 a week and you have 1