Question

Write the inverse fruction for the function. f(x)=1/2+4.then find the vaule of f(4) t

Answer 1

2x-8 = f^-1 (x)

0 = f^-1(4)

Explanation:

f(x) = 1/2x +4

To find the inverse exchange x and y and solve for y

y = 1/2x +4

Exchange x and y

x = 1/2y +4

Solve for y

Subtract 4 from each side

x-4 = 1/2y +4-4

x-4 = 1/2 y

Multiply by 2

2(x-4) = 1/y*2

2x-8 = y

2x-8 = f^-1 (x)

Let x=4

2(4) -8 = f^-1(4)

8-8 = f^-1(4)

0 = f^-1(4)