#### Answer

$d=\frac{\sqrt{kI}}{I}$

#### Work Step by Step

To solve for d, isolate d on one side of the equation.
$I=\frac{k}{d^2}$
Multiply both sides by $d^2$.
$I\times d^2=\frac{k}{d^2}\times d^2$
Simplify.
$I\times d^2=k$
Divide both sides by I.
$\frac{Id^2}{I}=\frac{k}{I}$
Simplify.
$d^2=\frac{k}{I}$
Take the square root of each side.
$\sqrt{d^2}=\sqrt{\frac{k}{I}}$
Simplify.
$d=\sqrt{\frac{k}{I}}$
Rationalize the denominator.
$d=\sqrt{\frac{k}{I}}=\frac{\sqrt k}{\sqrt I}=\frac{\sqrt k\times \sqrt I}{\sqrt I\times\sqrt I}=\frac{\sqrt{kI}}{I}$