[tex]y=4^x\\\\for\ x=-1\to y=4^{-1}=\dfrac{1}{4}=0.25\to(-1;\ 0.25)\\\\for\ x=-\dfrac{1}{2}\to y=4^{-\frac{1}{2}}=\dfrac{1}{4^\frac{1}{2}}=\dfrac{1}{\sqrt4}=\dfrac{1}{2}\to\left(-\dfrac{1}{2};\ \dfrac{1}{2}\right)\\\\for\ x=0\to y=4^0=1\to(0;\ 1)\\\\for\ x=\dfrac{1}{2}\to y=4^\frac{1}{2}=\sqrt4=2\to\left(\dfrac{1}{2};\ 2\right)\\\\for\ x=1\to y=4^1=4\to(1;\ 4)\\\\for\ x=2\to y=4^2=16\to (2;\ 16)[/tex]
[tex]\text{used:}\\\\a^{-n}=\dfrac{1}{a^n}\\\\a^\frac{1}{2}=\sqrt{a}[/tex]