Answer:
the square root of d
Step-by-step explanation:
if [tex]u^{2} = d[/tex] then the square root property would take the square root of each side of the equation. the square root of [tex]u^{2}[/tex] would just be [tex]u[/tex] because it's already squared and its exponent would just be cancelled out, while d would simply turn to [tex]\sqrt{d}[/tex].
meaning if [tex]u^{2} =d[/tex] then [tex]u=\sqrt{d}[/tex], because you've done the same thing to both sides of the equal sign, so they remain equivalent.
