A ladder 13m long leans against a wall. The foot of the ladder is pulled along the ground away from the wall, at the rate of 1.5m/sec. How fast is the angle `theta` between the ladder and the ground is changing when the foot of the ladder is 12m away from the wall.

Explanation

To solve the problem step by step, we will use the relationship between the lengths of the sides of the triangle formed by the ladder, the wall, and the ground, along with the rates of change of these lengths.

### Step 1: Understand the scenario
We have a right triangle where:
- The length of the ladder (hypotenuse) is constant at 13 m.
- The distance from the wall to the foot of the ladder (base) is changing, denoted as \( x \).
- The height of the ladder on the wall (perpendicular) is denoted as \( y \).

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