First, we need to remember to rules when working with exponents:
[tex]\begin{gathered} \frac{1}{b^a}=b^{-a} \\ \text{and} \\ b^a\cdot b^c=b^{a+c} \end{gathered}[/tex]
So, going back to our problem
[tex]\begin{gathered} \frac{2^{\frac{3}{4}}}{2^{\frac{1}{2}}} \\ =2^{\frac{3}{4}}\cdot2^{-\frac{1}{2}}=2^{\frac{3}{4}-\frac{1}{2}}=2^{\frac{1}{4}} \end{gathered}[/tex]
And this last result is equal to
[tex]\begin{gathered} 2^{\frac{1}{4}}=\sqrt[4]{2} \\ \Rightarrow\frac{2^{\frac{3}{4}}}{2^{\frac{1}{2}}}=\sqrt[4]{2} \end{gathered}[/tex]
