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Double and Half Angle Identities Worksheet

Explore and apply double and half angle identities to simplify trigonometric expressions and solve equations.

Grade 9 Math TrigonometryDouble and Half Angle Identities
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Includes

Multiple ChoiceFill in the BlanksShort AnswerTrue / False

Standards

CCSS.MATH.CONTENT.HSG.SRT.D.9

Topics

trigonometryidentitiesdouble anglehalf anglemath
6 sections · Free to use · Printable
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Double and Half Angle Identities

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Date:

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Read each question carefully and answer to the best of your ability. Show all your work for full credit.

1. Which of the following is equivalent to sin(2x)?

a

2sin(x)cos(x)

b

sin(x) + cos(x)

c

2sin(x)

d

cos(2x)

2. If cos(θ) = 3/5 and θ is in Quadrant I, what is sin(2θ)?

a

24/25

b

7/25

c

12/25

d

6/5

3. The identity for cos(2x) can be expressed as cos²(x) - sin²(x), or  , or  .

4. The half-angle identity for sin(x/2) is ±√((1 - cos(x)) /  ).

5. Given tan(θ) = -4/3 and θ is in Quadrant II, find the exact value of sin(θ/2).

6. The identity tan(2x) = (2tan(x))/(1 - tan²(x)) is always true for all values of x.

T

True

F

False