Question

Pls help with Trigonometric

Answer 1

The value of the given trigonometry function is 2√15/15

Half angles

Half angles are trigonometric identities used to express sine, cosine and tangent of half angles.

For instance the value of cos theta is expressed as shown below;

cosФ = cos(Ф/2+Ф/2)

cosФ = cos²Ф/2-sin²Ф/2
cosФ = cos²Ф/2-(1-cos²Ф/2)
cosФ  = 1 - 2cos²Ф/2

Given the following parameters

cosФ = -7/15

Substitute

cosФ  = 1 - 2cos²Ф/2

-7/15  = 1 - 2cos²Ф/2

-2cos²Ф/2 = -7/15 - 1

-2cos²Ф/2 = -8/15

cos²Ф/2 = 4/15
cosФ/2 = 2/√15

Rationalize

2/√15 * √15/√15

2√15/15

Hence the value of the given trigonometry function is 2√15/15

Learn more on trigonometry function here: brainly.com/question/2254074

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