Using trig properties and the angle of depression to solve a word problem

The video tutorial explains a trigonometry problem involving a warship and sonar technology. It describes how to determine the depth of a submarine using a 34-degree angle and a 4000-foot distance. The teacher guides through the process of identifying the right angle, hypotenuse, and opposite side, and applies the sine function to solve for the submarine's depth, resulting in a depth of 2236.77 feet.

How is the sine function used to find the depth of the submarine?

What final value is calculated for X, and what does it represent?