If A, B, C, D are the angles of a quadrilateral, then
\[
\frac{\tan A + \tan B + \tan C + \tan D}{\cot A + \cot B + \cot C + \cot D} =
\]
Show Hint
For angles in a quadrilateral, the sum of angles is \( 360^\circ \). This property can be used to simplify trigonometric expressions involving the angles.
Step 1: Use the property of angles in a quadrilateral. The sum of angles in a quadrilateral is \( 360^\circ \):
\[
A + B + C + D = 360^\circ
\]
Step 2: Express \(\tan\) and \(\cot\) in terms of each other. Recall that \(\cot \theta = \frac{1}{\tan \theta}\).
Step 3: Simplify the given expression.
\[
\frac{\tan A + \tan B + \tan C + \tan D}{\cot A + \cot B + \cot C + \cot D} = \frac{\tan A + \tan B + \tan C + \tan D}{\frac{1}{\tan A} + \frac{1}{\tan B} + \frac{1}{\tan C} + \frac{1}{\tan D}}
\]
\[
= \frac{\tan A + \tan B + \tan C + \tan D}{\frac{\tan B \tan C \tan D + \tan A \tan C \tan D + \tan A \tan B \tan D + \tan A \tan B \tan C}{\tan A \tan B \tan C \tan D}}
\]
\[
= \frac{(\tan A + \tan B + \tan C + \tan D) \cdot (\tan A \tan B \tan C \tan D)}{\tan B \tan C \tan D + \tan A \tan C \tan D + \tan A \tan B \tan D + \tan A \tan B \tan C}
\]
\[
= \tan A \tan B \tan C \tan D
\]
Step 4: Determine the correct answer. The expression simplifies to \(\tan A \tan B \tan C \tan D\).