Get the answers you've been looking for with the help of IDNLearn.com's expert community. Whether your question is simple or complex, our community is here to provide detailed and trustworthy answers quickly and effectively.

Sienna has 80 yards of fencing to enclose a rectangular area. Find the dimensions that maximize the enclosed area. What is the maximum area?

Sagot :

[tex]2x+2y=80\ \ \ /:2\\\\2x:2+2y:2=80:2\\\\x+y=40\ \ \ /-x\\\\y=40-x\ \ \ (D_x:x\in(0;\ 40))[/tex]

[tex]Area=xy\\\\substitute\ y=40-x\\\\Area=x(40-x)=-x^2+40\\(it's\ quadratic\ function\ where\ a=-1;b=40;c=0)\\\\vertex\ of\ parabola:p=\frac{-b}{2a}\to p=\frac{-40}{2\cdot(-1)}=\frac{-40}{-2}=20-it's\ max\\\\x=20\ then\ y=40-20=20\\\\Answer:dimensions\ of\ rectangular\ is\ 20\ yd\ \times\ 20\ yd,\\and\ area\ is\ 20^2=400\ yd^2.[/tex]
View image Аноним