What is the inverse of the function below?

[tex]\[ f(x) = 2^x + 6 \][/tex]

A. [tex]\[ f^{-1}(x) = 6 + \log_2 x \][/tex]

B. [tex]\[ f^{-1}(x) = \log_2(x + 6) \][/tex]

C. [tex]\[ f^{-1}(x) = 6 \log_2 x \][/tex]

D. [tex]\[ f^{-1}(x) = \log_2(x - 6) \][/tex]



Answer :

To find the inverse of the function [tex]\( f(x) = 2^x + 6 \)[/tex], we need to follow these steps:

1. Replace [tex]\( f(x) \)[/tex] with [tex]\( y \)[/tex]:
[tex]\[ y = 2^x + 6 \][/tex]

2. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to start finding the inverse:
[tex]\[ x = 2^y + 6 \][/tex]

3. Solve for [tex]\( y \)[/tex]:
- First, isolate the exponential term:
[tex]\[ x - 6 = 2^y \][/tex]
- Next, take the logarithm base 2 of both sides to solve for [tex]\( y \)[/tex]:
[tex]\[ \log_2(x - 6) = y \][/tex]

4. Thus, the inverse function [tex]\( f^{-1}(x) \)[/tex] is:
[tex]\[ f^{-1}(x) = \log_2(x - 6) \][/tex]

Therefore, the correct option is:
D. [tex]\( f^{-1}(x) = \log_2(x - 6) \)[/tex]