Answer:
Explanation:
1). f(x) = 3x⁵
Step - 1
Convert the given function in the form of an equation.
y = 3x⁵
Step - 2
Interchange x by y.
Step - 3
Solve the equation for y
x = 3y⁵
y⁵ =

![y=\sqrt[5]{(x)/(3)}](https://img.qammunity.org/2021/formulas/mathematics/college/6itcdu27b3z9fdj947f5uydyuhqgz9xonr.png)
Step - 4
Convert the equation into function.
![f^(-1)(x)=\sqrt[5]{(x)/(3)}](https://img.qammunity.org/2021/formulas/mathematics/college/wniq7497f5bkg0ppiz6814gfsht854s9ms.png)
Correct.
2). f(x) = 3x + 7
Step - 1
y = 3x + 7
Step - 2
x = 3y + 7
Step - 3
3y = x - 7
y =

Step - 4
Correct.
3). f(x) = 6 + 4x³
Step - 1
y = 4x³ + 6
Step - 2
x = 4y³ + 6
Step - 3
y =
![\sqrt[3]{(1)/(4)(x-6)}](https://img.qammunity.org/2021/formulas/mathematics/college/7bonxbfrqpwxilhp9te2i0ytixxz12lts3.png)
Step - 4
![f^(-1)(x)=\sqrt[3]{(1)/(4)(x-6)}](https://img.qammunity.org/2021/formulas/mathematics/college/5b3pnb5nv7ko9ixd25lbvb1vi8vroanoq1.png)
Incorrect.