Here we have a quadratic function and we want to find the value of a constant with a given restriction.
We will find that c = 8.
So we have the function:
[tex]f(x) = -2c + cx - x^2[/tex]
We know that:
[tex]f(5)^{-1} = -1 = \frac{1}{-2c + c\cdot 5 - (5)^2}[/tex]
Notice that the above equation means that:
[tex]-2c + c\cdot5 - (5)^2 = -1[/tex]
Then we just need to solve the above equation for c:
[tex]-2c + 5c - (5)^2 = -1\\\\(-2 + 5)\cdot c - 25 = -1\\\\3\cdot c = -1 + 25\\\\3\cdot c = 24\\\\c = 24/3 = 8[/tex]
So we found that the value of c is 8.
This means that the function is:
[tex]f(x) = -16 + 8\cdot x - x^2[/tex]
You can see the graph below:
If you want to learn more, you can read:
https://brainly.com/question/24215686
