Answer :
To determine the domain of this function, we have to remember that there are not real square roots for negative values, it means
[tex]4x-3\ge0[/tex]Solve for x in the inequality
[tex]\begin{gathered} 4x-3\ge0 \\ 4x\ge3 \\ x\ge\frac{3}{4} \\ \end{gathered}[/tex]x is more than or equal 3/4
In set builder notation it is written this way
[tex]D=\lbrace x\in R\text{ l }x\ge\frac{3}{4}\rbrace[/tex]