Suppose you have 76 feet of fencing to enclose a rectangular dog pen. The function A=38x-x^2 , where x = width, gives you the area of the dog pen in square feet. What width gives you the maximum area? What is the maximum area? Round to the nearest tenth as necessary.

a. width = 19 ft; area = 361 ft2

b. width = 38 ft; area = 760 ft2

c. width = 38 ft; area = 361 ft2

d. width = 19 ft; area = 1083 ft2

Question

Suppose you have 76 feet of fencing to enclose a rectangular dog pen. The function A=38x-x^2 , where x = width, gives you the area of the dog pen in square feet. What width gives you the maximum area? What is the maximum area? Round to the nearest tenth as necessary.

	a. width = 19 ft; area = 361 ft2

	b. width = 38 ft; area = 760 ft2

	c. width = 38 ft; area = 361 ft2

	d. width = 19 ft; area = 1083 ft2

phi · Answer

double posting is rude

anonymous · Answer

bye

phi · Answer

there is a way to solve this using calculus  and a way to solve it by finding the vertex of a parabola.  which way to solve it depends on what you are studying

phi · Answer

another way to solve it is try each of the choices and pick the one that gives the biggest area... that is not quite kosher,  but if you are stuck on  a test, always remember that trick

anonymous · Answer

k -__-

phi · Answer

looking at your other posts,  it looks like you are studying parabolas.

find the vertex of this parabola,  using  -b/2a  where a,b,c are the coefficients in
ax^2 + bx + c

anonymous · Answer

yea im doing my work on the computer a website called novanet but im fine this site dont help me much and i know pple are not supposed to just give answer but im on a time limit and this site take a very long time to get me answer so im just going to log out

phi · Answer

for this problem, have you figured out what a and b are  in
 A=38x-x^2
which can be written as

$$ A = -1 x^2 + 38x $$

anonymous · Answer

im off ... bye