SOLUTION:
Case: Quadratic
Method:
a) She makes a profit between the prices where the Profit P(x) is greater than 0.
Plotting a graph
From the graph,
She makes a profit when the prices are between $0.25 and $49.75
b)
To make the maximum profit
![\begin{gathered} P(x)=-2x^2+100x-25 \\ P(x)=-2[x^2-50x]-25 \\ P(x)=-2[x^2-50x+625-625]-25 \\ P(x)=-2[(x-25)^2-625]-25 \\ P(x)=-2(x-25)^2+1250-25 \\ P(x)=-2(x-25)^2+1225 \\ When\text{ }the\text{ }price\text{ }x=25\text{ }the\text{ }profit\text{ }is\text{ }maximum \\ P(25)=1225 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/is545efnhyxvx40llvii76zad6z772fvfi.png)
Final answers:
a) Between $0.25 and $49.75
b) Price, x = 25