Given cosine, evaluate the half angle for sine

The video tutorial explains how to find the sine of U/2 given the cosine of U. It introduces the problem, applies the formula without needing a triangle, simplifies the expression, rationalizes the denominator, and discusses the importance of sign based on angle constraints. The tutorial emphasizes understanding the formula and the conditions under which the sine value is positive.

What is the given value of cosine U in the problem?

• 3/5

• 4/5

• 5/3

• 2/5

What is the initial expression set up to find sine of U/2?

• 1 - 3/5 / 2

• 1 + 3/5 / 2

• 1 - 2/5 / 2

• 1 + 2/5 / 2

After simplifying, what is the expression reduced to before rationalizing?

• 3/5

• 4/5

• 2/5

• 1/5

What is the final answer after rationalizing the denominator?

• sqrt 2 / 5

• sqrt 3 / 5

• sqrt 5 / 3

• sqrt 5 / 5

Why is the sine value positive in this problem?

• Because the angle is in the first quadrant

• Because the angle is negative

• Because cosine is positive

• Because the angle is in the second quadrant