Using the half angle formula for sine

The video tutorial explains how to handle angles not on the unit circle by creating triangles. It covers the placement of angles in different quadrants, focusing on the second quadrant where cosine is negative. The tutorial demonstrates finding the exact value of sine of U/2 using the Pythagorean theorem and simplifies the expression. The session concludes with addressing student questions.

What is the cosine of angle U given that it equals -12/13?

In which quadrants can you draw a triangle for angle U if it is between π/2 and π?

How do you determine the sign of the cosine in the second quadrant?

What is the formula for sine of U/2?

How do you apply the Pythagorean theorem to find the missing side of the triangle?

What is the significance of the Pythagorean triples mentioned in the context of this problem?

What is the final answer for sine of U/2 after rationalizing the denominator?