Precalculus : Fundamental Trigonometric Identities

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #175 : Trigonometric Functions

Possible Answers:

Correct answer:

Explanation:

Using these basic identities:

we find the original expression to be

which simplifies to

.

Further simplifying:

The cosines cancel, giving us

Example Question #176 : Trigonometric Functions

Which of the following is the best answer for ?

Possible Answers:

Correct answer:

Explanation:

Write the Pythagorean identity.

Substract  from both sides.

The other answers are incorrect.

Example Question #61 : Fundamental Trigonometric Identities

Express  in terms of only sines and cosines.

Possible Answers:

Correct answer:

Explanation:

The correct answer is . Begin by substituting , and . This gives us:

.

Example Question #175 : Trigonometric Functions

Express  in terms of only sines and cosines.

Possible Answers:

Correct answer:

Explanation:

To solve this problem, use the identities , and . Then we get 

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