Respuesta :

Answer:

6.

Step-by-step explanation:

f(x) = √(x - 4)      x > 4

y = √((x - 4)

Square both sides

y^2 = x - 4

x = y^2 - 4

So the inverse:

f-1(x) = x^2 + 4

f(-1)'(x) = 2x

When x = 3

f(-1)'(3) = 2(3) = 6.