Precalculus : Trigonometric Functions

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #16 :Find The Value Of Any Of The Six Trigonometric Functions

Find the value of.

Possible Answers:

Correct answer:

解释,nation:

Since

we begin by finding the value of.

.

Then,

Example Question #17 :Find The Value Of Any Of The Six Trigonometric Functions

Determine the value of:

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Correct answer:

解释,nation:

确定的价值, simplify cotangent into sine and cosine.

Example Question #18 :Find The Value Of Any Of The Six Trigonometric Functions

Find the value of, if possible.

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Correct answer:

解释,nation:

In order to solve, split up the expression into 2 parts.

Example Question #19 :Find The Value Of Any Of The Six Trigonometric Functions

Compute, if possible.

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Correct answer:

解释,nation:

Rewrite the expression in terms of cosine.

Evaluate the value of在第四象限。

Substitute it back to the simplified expression of.

Example Question #20 :Find The Value Of Any Of The Six Trigonometric Functions

Determine

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Correct answer:

解释,nation:

Remember that:

Example Question #21 :Find The Value Of Any Of The Six Trigonometric Functions

What is the value of?

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Correct answer:

解释,nation:

The sine of an angle corresponds to the y-component of the triangle in the unit circle. The angleis a special angle. In the unit circle, the hypotenuse is the radius of the unit circle, which is 1. Since the angle is, the triangle is an isosceles right triangle, or a 45-45-90.

Use the Pythagorean Theorem to solve for the leg. Both legs will be equal to each other.

Rationalize the denominator.

Therefore,.

Example Question #1 :Prove Trigonometric Identities

Simplify:

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Correct answer:

解释,nation:

To simplify, find the common denominator and multiply the numerator accordingly.

The numerator is an identity.

Substitute the identity and simplify.

Example Question #2 :Prove Trigonometric Identities

Evaluate in terms of sines and cosines:

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Correct answer:

解释,nation:

Convertinto its sines and cosines.

Example Question #3 :Prove Trigonometric Identities

Simplify the following:

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The expression is already in simplified form

Correct answer:

解释,nation:

First factor out sine x.

Notice that a Pythagorean Identity is present.

The identity needed for this problem is:

Using this identity the equation becomes,

.

Example Question #4 :Prove Trigonometric Identities

Simplify the expression

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Correct answer:

解释,nation:

To simplify, use the trigonometric identitiesandto rewrite both halves of the expression:

Then combine using an exponent to simplify:

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