Please check pictureQuestionWhich of the following is a power function? Select all correct answers.Select all that apply:f(x)=6⋅16xf(x)=4x−−√9f(x)=10⋅3xf(x)=5⋅15x f(x)=−18x−−√3

Answer:
The correct options are:
[tex]\begin{gathered} f(x)=4\sqrt[9]{x} \\ . \\ f(x)=-18\sqrt[3]{x} \end{gathered}[/tex]Explanation:
A power function is a function that has the variable to the power of some fixed real number. A power function can't have the variable (x, in this problem) in the exponent.
Then, the only two option that follow this are:
[tex]\begin{gathered} f(x)=4\sqrt[9]{x} \\ . \\ f(x)=-18\sqrt[3]{x} \end{gathered}[/tex]Because we can rewrite the exponent as:
[tex]\begin{gathered} f(x)=4\sqrt[9]{x}=4x^{\frac{1}{9}} \\ . \\ f(x)=-18\sqrt[3]{x}=-18x^{\frac{1}{3}} \end{gathered}[/tex]Which is clearly, the variable to the power of a real number.