A homeowner has an octagonal gazebo inside a circular area. Each vertex of the gazebo lies on the circumference of the circular area. The area that is inside the circle, but outside the gazebo, requires mulch. This area is represented by the function [tex]m(x)[/tex], where [tex]x[/tex] is the length of the radius of the circle in feet. The homeowner estimates that he will pay [tex]\$ 1.50[/tex] per square foot of mulch. This cost is represented by the function [tex]g(m)[/tex], where [tex]m[/tex] is the area requiring mulch.

[tex]\[ \begin{array}{l}
m(x) = \pi x^2 - 2 \sqrt{2} x^2 \\
g(m) = 1.50 m
\end{array} \][/tex]

Which expression represents the cost of the mulch based on the radius of the circle?

A. [tex]1.50(\pi x^2 - 2 \sqrt{2} x^2)[/tex]
B. [tex]\pi(1.50 x)^2 - 2 \sqrt{2} x^2[/tex]
C. [tex]x(1.50 x)^2 - 2 \sqrt{2}(1.50 x)^2[/tex]
D. [tex]1.50(\pi(1.50 x)^2 - 2 \sqrt{2}(1.50 x)^2)[/tex]



Answer :

Let's analyze the problem step-by-step based on the functions provided and the goal of finding the correct cost expression.

1. Understanding the Functions:
- The first function provided is [tex]\( m(x) = \pi x^2 - 2\sqrt{2} x^2 \)[/tex]. This represents the area that requires mulch, where [tex]\( x \)[/tex] is the radius of the circular area. Essentially, [tex]\( m(x) \)[/tex] gives the area of the circle minus the area of the octagon inscribed within it.
- The second function, [tex]\( g(m) = 1.50 m \)[/tex], represents the cost of mulching the area requiring mulch. This indicates that the cost is \$1.50 per square foot of mulch.

2. Formulating the Cost Expression:
- Given the functions [tex]\( m(x) \)[/tex] and [tex]\( g(m) \)[/tex], we need to substitute [tex]\( m(x) \)[/tex] into [tex]\( g \)[/tex] to get the cost based on the radius of the circle:
[tex]\[ g(m(x)) = 1.50 \cdot m(x) \][/tex]
- Substituting [tex]\( m(x) \)[/tex] into the equation:
[tex]\[ g(m(x)) = 1.50 \left( \pi x^2 - 2\sqrt{2} x^2 \right) \][/tex]

3. Comparing with the Given Options:
- Now we compare the derived expression with the provided options:
1. [tex]\( 1.50 \left( \pi x^2 - 2 \sqrt{2} x^2 \right) \)[/tex]
2. [tex]\( \pi (1.50 x)^2 - 2 \sqrt{2} x^2 \)[/tex]
3. [tex]\( x (1.50 x)^2 - 2 \sqrt{2} (1.50 x)^2 \)[/tex]
4. [tex]\( 1.50 \left( \pi (1.50 x)^2 - 2 \sqrt{2} (1.50 x)^2 \right) \)[/tex]

Clearly, the derived equation matches the expression given in option 1.

Therefore, the correct expression representing the cost of the mulch based on the radius of the circle is:

[tex]\[ 1.50 \left( \pi x^2 - 2 \sqrt{2} x^2 \right) \][/tex]