Using the additions of two angles and cosine

The video tutorial explains how to find the exact value of cosine for 13π/12 using the unit circle and the sum formula for cosine. The instructor breaks down the angle into the sum of two angles on the unit circle, applies the sum formula, and calculates the exact values using known coordinates. The process involves identifying the correct angles, applying trigonometric identities, and simplifying the result to find the cosine of 13π/12.

What is the exact value of cosine at 13π/12 using the unit circle?

How can you break down the angle 13π/12 into two angles that are on the unit circle?

Explain how to use the sum formula for cosine to find the value of cosine at 13π/12.

What values do you need to find for the angles 3π/4 and π/3 to calculate cosine of 13π/12?

What are the coordinates for the angle 3π/4 on the unit circle?