Question

Given the function f(x) = -2c + cx - x^2? and f^-1(5) = -1, find c.

Answer 1

c = - 2

Explanation:

Given inverse function

`f^(-1)` (5) = - 1 , then

f(- 1) = 5 , that is

- 2c + c(- 1) - (- 1)² = 5

- 2c - c - 1 = 5

- 3c - 1 = 5 ( add 1 to both sides )

- 3c = 6 ( divide both sides by - 3 )

c = - 2