To find the inverse, we swap the variables y and x, then solve for the new y.
3a.
![y=(3)/(x-1)](https://img.qammunity.org/2019/formulas/mathematics/high-school/qyo9htgorn8rltb03b2qsebbdo7krj1g97.png)
Swapping the variables:
![x=(3)/(y-1)](https://img.qammunity.org/2019/formulas/mathematics/high-school/bukbor9lx7syvn9reg9j2a06uui6fibqr0.png)
Solving for y:
![x(y-1)=3 \\ y-1= (3)/(x) \\ y=1+(3)/(x)](https://img.qammunity.org/2019/formulas/mathematics/high-school/ixjcusddj4m28v40f9nsupfjcijw0936jy.png)
The domain of this inverse is
![x ≠ 0](https://img.qammunity.org/2019/formulas/mathematics/high-school/riwrbkpy6znzyr0g3pie9jlowpkdcjtlyg.png)
.
3b.
![y=x^2-1](https://img.qammunity.org/2019/formulas/mathematics/high-school/am4tmkgmdkwxnz139u6l24dpusuvgphkqz.png)
Swapping:
![x = y^2 - 1](https://img.qammunity.org/2019/formulas/mathematics/high-school/m538stb2x7fd33u7leye60y7u1gzkbiyfc.png)
Solving for y:
![y^2 = x + 1 \\ y = √(x+1)](https://img.qammunity.org/2019/formulas/mathematics/high-school/agt3rs6acxl1q2oi2ksgz9q7wv9bp9k0y4.png)
The domain of this inverse is
![x ≥ -1](https://img.qammunity.org/2019/formulas/mathematics/high-school/ge5cpg7ptb3iyehq6x8nxzpjfe3wpj99ym.png)
.
3c.
![y=\sqrt[3]{(x-7)/(3)}](https://img.qammunity.org/2019/formulas/mathematics/high-school/y5t7ljsnpcnfwfe238zftytf2o3oo7z57n.png)
Swapping:
![x=\sqrt[3]{(y-7)/(3)}](https://img.qammunity.org/2019/formulas/mathematics/high-school/tg01do9nitcb3p0mgx4vyhuqg5dkfxqf6n.png)
Solving for y:
![x^3=(y-7)/(3) \\ y-7=3x^3 \\ y=3x^3+7](https://img.qammunity.org/2019/formulas/mathematics/high-school/rjacw7xpbgzknn40cs7rasa9t0jovy8gn8.png)
The domain of this inverse is all real numbers.
4a.
![y=(3)/(x-1)](https://img.qammunity.org/2019/formulas/mathematics/high-school/qyo9htgorn8rltb03b2qsebbdo7krj1g97.png)
,
![y=1+(3)/(x)](https://img.qammunity.org/2019/formulas/mathematics/high-school/75nxcnnekowjxfjh49n47gizwevvkcctwj.png)
![y=(3)/((1+(3)/(x))-1) \\ y=(3)/(((3)/(x))) \\ y=x](https://img.qammunity.org/2019/formulas/mathematics/high-school/jzo2qsuat2nyj2qlvzd1i39hsvgw4ht47y.png)
4c.
![y=\sqrt[3]{(x-7)/(3)}](https://img.qammunity.org/2019/formulas/mathematics/high-school/y5t7ljsnpcnfwfe238zftytf2o3oo7z57n.png)
,
![y=3x^3+7](https://img.qammunity.org/2019/formulas/mathematics/high-school/ygta3hhys3vq3ngtn1px38a68uoo1oqgfh.png)
![y=\sqrt[3]{((3x^3+7)-7)/(3)} \\ y=\sqrt[3]{(3x^3)/(3)} \\ y=\sqrt[3]{x^3} \\ y=x](https://img.qammunity.org/2019/formulas/mathematics/high-school/3egl865160qf7xfptj6wb6ute2p8k8errr.png)
![y=3(\sqrt[3]{(x-7)/(3)})^3+7 \\ y = 3({(x-7)/(3)})+7 \\ y = (x-7)+7 \\ y=x](https://img.qammunity.org/2019/formulas/mathematics/high-school/p9r9d5t3h4gfxuapdd0ymft72u1dl99mat.png)