A quadratic function describes the relationship between the number of products x and the overall profits for a company.
The roots of the quadratic function are given as x = 0 and x = 28. We also know the graph's vertex is located at (14, -40).
The quadratic equation can be written in terms of its roots x1 and x2 as:
![f(x)=a(x-x_1)(x-x_2)](https://img.qammunity.org/2023/formulas/mathematics/college/ypakdambvkw6j2jh9xvx590vr10vh74bos.png)
Substituting the given values:
![\begin{gathered} f(x)=a(x-0)(x-28) \\ \\ f(x)=ax(x-28) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/vg0mnqqvcc5mdo0xh3npjfb8fe7fu2uead.png)
We can find the value of a by plugging in the coordinates of the vertex:
![f(14)=a\cdot14(14-28)=-40](https://img.qammunity.org/2023/formulas/mathematics/college/u8pcx5dkkhqf47vn48c7pma80fcmdv936p.png)
Solving for a:
![a=(-40)/(-196)=(10)/(49)](https://img.qammunity.org/2023/formulas/mathematics/college/jvh8xod6lark6zeenwsmyizjf0wanyndth.png)
Substituting into the equation:
![f(x)=(10)/(49)x(x-28)](https://img.qammunity.org/2023/formulas/mathematics/college/ofmo579o1vi43ncqru3pn3d7tkl6a25t3b.png)
The graph of the function is given below:
The company actually loses money on their first few products, but once they hit 28 items, they break even again.
The worst-case scenario is that they produce 14 items, as they will have a profit of -40 dollars. The first root tells us the profit will be 0 when 0 products are sold.