Question

If f(x) and f-1 (x)
are inverse functions of each other and f(x) = 2x+5, what is f-1 (8)?​

Answer 1

3/2 B

Explanation:

Edge

Answer 2

For this case we have the following function:

f (x) = 2x + 5

Clearing x we have:

2x = y - 5

x = (y-5) / 2

Rewriting:

f (x) ^ - 1 = (x-5) / 2

Evaluating x = 8:

f (8) ^ - 1 = (8-5) / 2

f (8) ^ - 1 = 3/2

Answer:

f (8) ^ - 1 = 3/2

option 2