Write the conditions for total internal reflection.

Explanation

To determine the conditions for total internal reflection, we need to consider the behavior of light as it travels between two different media. Here’s a step-by-step solution outlining the conditions:

### Step 1: Identify the Media
- Total internal reflection occurs at the interface between two media. The first medium (Medium 1) must be denser than the second medium (Medium 2).

### Step 2: Direction of Light
- Light must be traveling from the denser medium (Medium 1) to the rarer medium (Medium 2). This means that the refractive index of Medium 1 should be greater than that of Medium 2.

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