Tell What Restrictions, If Any, Must Be Made On $\mathrm{d}$ And $\mathrm{k}$

Short Answer

Tell what restrictions, if any, must be made on $\mathrm{d}$ and $\mathrm{k}$ (both real numbers) to guarantee that $\mathrm{t}$ is a real number. Assume that the denominator is not zero.
$t=\frac{\sqrt{d k}}{k}$