SOLUTION
We want to find the function that has the greatest value for x = 3
Note that the dot means multiplication
For A.
[tex]\begin{gathered} f\mleft(x\mright)=2\times4^x \\ f(3)=2\times4^3 \\ =128 \end{gathered}[/tex]
For B
[tex]\begin{gathered} f(x)=4\times2^x \\ f(3)=4\times2^3 \\ =32 \end{gathered}[/tex]
For C
[tex]\begin{gathered} f(x)=4\times x^2 \\ f(3)=4\times3^2 \\ =36 \end{gathered}[/tex]
For D
[tex]\begin{gathered} f(x)=2\times x^4 \\ f(3)=2\times3^4 \\ =162 \end{gathered}[/tex]
Hence the from our calculation, we can see that the answer is D. which is 162
