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.

In which quadrant is the angle U located if π/2 < U < π?

• Fourth Quadrant

• Third Quadrant

• Second Quadrant

• First Quadrant

What is the sign of the cosine function in the second quadrant?

• Undefined

• Zero

• Negative

• Positive

Which theorem is used to find the missing side of a right triangle?

• Tangent Rule

• Cosine Rule

• Pythagorean Theorem

• Sine Rule

What is the value of H if 12^2 + H^2 = 13^2?

• 6

• 3

• 4

• 5

What is the formula for sine of U/2?

• 1 + cosine(U) / 2

• 1 - cosine(U) / 2

• cosine(U) / 2

• sine(U) / 2

How do you simplify the expression sqrt(25/26)?

• sqrt(25) / 26

• 5 / 26

• sqrt(26) / 5

• 5 / sqrt(26)

What is the final simplified form of ± 5 sqrt(26) over 26?

• ± 5 / 26

• ± 26 / 5

• ± sqrt(26) / 5

• ± 5 sqrt(26) / 26