Using the half angle of sine to evaluate an angle

The video tutorial explains how to evaluate the sine of 3π/8, which is not on the unit circle. Initially, the sum and difference formulas are considered, but the half-angle formula is introduced as a more efficient method. The tutorial demonstrates how to apply the half-angle formula, simplify the expression, and arrive at the final result. Key concepts include understanding the unit circle, using trigonometric identities, and applying algebraic simplification techniques.

What is the sine of three π / 8 and why can't we find its exact value using the unit circle?

Explain the sum and difference formulas mentioned in the context of evaluating trigonometric functions.

What does the half angle formula state for sine, and how is it applied in this context?

How do you determine the cosine of an angle when using the half angle formula?

What quadrant does the angle U / 2 fall into, and how does that affect the sign of the sine value?

Describe the process of simplifying the expression derived from the half angle formula.

What is the final answer for the sine of three π / 8 after applying the half angle formula, and how is it expressed?