Question

Let f(x) = 2x + 2. Solve f−1(x) when x = 4. (1 point)

Answer 1

If f(x) = 2x + 2 is invertible, then its inverse is another function f ⁻¹(x) such that

f(f ⁻¹(x)) = 2 f ⁻¹(x) + 2 = x

Solve for f ⁻¹(x) :

2 f ⁻¹(x) + 2 = x

2 f ⁻¹(x) = x - 2

f ⁻¹(x) = (x - 2)/2 = x/2 - 1

Then when x = 4, we have f ⁻¹ (4) = 4/2 - 1 = 2 - 1 = 1.

Answer 2

1

Explanation:

First, find the inverse of the original function.

x = 2y + 2

x-2/2

Second, substitute x with 4 and solve.

4-2/2

2/2

1

Best of Luck!