Determine the Value of Theta When Given the Value of Cosine

The video tutorial explains how to find the value of Theta in degrees and radians without a calculator. It focuses on the unit circle, specifically the first quadrant, and identifies the angle where the cosine is equal to sqrt 2/2. The solution is found to be π/4 or 45 degrees. The tutorial emphasizes understanding the unit circle and the relationship between angles and coordinates.

Why is it important to focus only on the first quadrant when solving for angles in this context?

What is the relationship between the cosine of an angle and the x-coordinate on the unit circle?