Given f(x)=2^(x+1) -3, what is f^ –1(x)? (It is asking for the inverse).A. f ^–1(x) = log2(x + 3) – 1B. f ^–1(x) = log2(x – 1) + 3C. f ^–1(x) = log2(x + 1) – 3D. f ^–1(x) = log2(x – 3) + 1

Respuesta :

Given the function:

[tex]f(x)=2^{(x+1)}-3[/tex]

You can find its inverse as follows:

1. Rewrite the function using:

[tex]y=f(x)[/tex]

Then:

[tex]y=2^{(x+1)}-3[/tex]

2. Solve for "x":

- Add 3 to both sides of the equation:

[tex]y+3=2^{(x+1)}-3+3[/tex]

[tex]y+3=2^{(x+1)}[/tex]

- Apply logarithm to both sides:

[tex]log(y+3)=log(2)^{(x+1)}[/tex]

- Apply the Power Property for Logarithms:

[tex]log(m)^n=nlog(m)[/tex]

Then:

[tex]log(y+3)=(x+1)log(2)^[/tex]

- Divide both sides of the equation by:

[tex]log(2)[/tex]

You get:

[tex]\frac{log(y+3)}{log(2)}=\frac{x+1}{log(2)}[/tex][tex]\frac{log(y+3)}{log(2)}=x+1[/tex]

- Subtract 1 from both sides:

[tex]\frac{log(y+3)}{log(2)}-1=x+1-1[/tex][tex]\frac{log(y+3)}{log(2)}-1=x[/tex]

3. Swap variables:

[tex]\frac{log(y+3)}{log(2)}-1=x+1-1[/tex][tex]y=\frac{log(x+3)}{log(2)}-1[/tex]

4. Rewrite it in this form:

[tex]f^{-1}(x)=\frac{log(x+3)}{log(2)}-1[/tex]

Hence, the answer is:

[tex]f^{-1}(x)=\frac{log(x+3)}{log(2)}-1[/tex]