Question

If f(x) = log3 (x + 1), what is f−1(2)?
1
8
10
27

Answer 1

We are asked in the problem to determine f−1(2) given the function f(x) = log3 (x + 1). The first step is to determine the inverse of f(x).

f-1(x) :

y = log3(x+1)
x= log3(y+1)
3^x = y +1
y = 3^x - 1
if x = 2
y = 8

Answer 2

Option B. 8

Explanation:

Given function is
`f(x)=log_(3)(x + 1)`

Now we have to find the value of
`f^(-1)(x)`.

Since
`f(x)= y=log_(3)(x+1)`

`3^(y)=(x + 1)`

Now for
`f^(-1)(x)`

we will replace x by y.

`3^(x)=y + 1`

`y=3^(x)-1`

`f^(-1)(x)=3^(x)-1`

Now we put the value of x = 2

y = 3²- 1 = 9-1 = 8

Therefore
`f^(-1)(2)=8` is the answer.