Question

Write the inverse function for the function, ƒ(x) =x + 4. Then, find the value of ƒ -1(4). Type your answers in the box.

Answer 1

inverse of f(x)= x+4 is

`f - 1(x) = x - 4`

f-1(4)= 0

Explanation:

replace f-1(x) by y:

`y = x + 4`

then, rearrange the equation to make x the subject.

`x = y - 4`

now change the y to x, and the x at the beginning to f-1(x). you get:

`f - 1(x) = x - 4`

which is the answer.

for the second part, simply replace the x in equation that we got above to get:

`f - 1(x) = 4 - 4`

so, f-1(4) = 0