The function is given as,
[tex]y=4^x[/tex]
For x = -1 , the value of y is calculated as,
[tex]\begin{gathered} y=4^{-1} \\ y\text{ = }\frac{1}{4} \\ y\text{ = 0.25} \end{gathered}[/tex]
For x = 0 , the value of y is calculated as,
[tex]\begin{gathered} y=4^0 \\ y\text{ = 1} \end{gathered}[/tex]
For x = 1 , the value of y is calculated as,
[tex]\begin{gathered} y=4^1 \\ y\text{ = 4} \end{gathered}[/tex]
For x = 2, the value of y is calculated as,
[tex]\begin{gathered} y=4^2 \\ y\text{ = 16} \end{gathered}[/tex]
