The function A(x) = -x(10 – x) describes the area A of a rectangular flower garden, where x is the width in yards. What is the maximum area of the garden?

Respuesta :

Answer:

Maximum area of the rectangular park is 75 square yards.

Step-by-step explanation:

The function A(x) = -x(10 - x) describes the area of a rectangular flower garden.

A(x) = -x(10 - x)

Where x = width of the garden

For the maximum area we will find the derivative of the given function and equate it to zero.

[tex]\frac{dA}{dx}=0[/tex]

[tex]\frac{dA}{dx}=\frac{d}{dx}[-x(10-x)][/tex] = 0

[tex]A'(x)=-10+2x[/tex]

For A'(x) = 0,

2x - 10 = 0

x = 5 yards

For A(5) = 5(10 + 5)

             = 75 square yards

Therefore, the maximum area of the rectangular garden is 75 yards².

Answer:

No, maxima point found!

Step-by-step explanation:

Given function:

[tex]A(x)=-x(10-x)[/tex]

where:

A = area of rectangular flower garden

x= side of rectangle

Now for the function to yield extrema:

[tex]\frac{d}{dx}(A) =0[/tex]

[tex]\frac{d}{dx} (-10x+x^2)=0[/tex]

[tex]-10+2x=0[/tex]

[tex]x=5[/tex] will be the point of extrema.

Now we check for second derivative A" at x=5:

[tex]A"=\frac{d}{dx} (A')[/tex]

[tex]A"=x[/tex]

[tex]A"=5>0[/tex] so it yields minima at this point and hence we do not have a maxima for this function.