Half Angle Identities

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Show your work for each problem.

1.
Which formula correctly represents ?
1. a)
2. b)
3. c)
4. d)
2.
To find using a half-angle formula, what angle should you use for ?
1. a)
2. b)
3. c)
4. d)
3.
The half-angle formula for sine has a sign. If , which sign should you use?
1. a) (positive)
2. b)Neither
3. c)Both are correct
4. d) (negative)
4.
If , what is ?
5.
What is calculated using the half-angle formula with ?
1. a)
2. b)
3. c)
4. d)
6.
Using , calculate . Give your answer as a fraction with in the numerator.
7.
Find the exact value of using the half-angle formula.
8.
Which of these is a valid formula for ?
1. a)
2. b)
3. c)
4. d)
9.
Calculate using the half-angle formula. Express as where is an integer.
10.
Find the exact value of .
11.
If , what is the sign of ?
1. a)Zero
2. b)Positive
3. c)Negative
4. d)Undefined
12.
Using half-angle formulas, find . Express your answer as and give the value of .
13.
Find the exact value of .
14.
If and is in Quadrant I, find . Express as a fraction.
15.
Find using the half-angle formula.