Precalculus : Find the decimal value of a trigonometric function

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #1 : Evaluating Trig Functions

Find the value of  to the nearest tenth if  and .

Possible Answers:

Correct answer:

Explanation:

Rewrite  in terms of sine and cosine.

Substitute the known values and evaluate.

The answer to the nearest tenth is .

Example Question #2 : Evaluating Trig Functions

Determine the value of  in decimal form.

Possible Answers:

Correct answer:

Explanation:

Ensure the calculator is in radian mode since the expression shows the angle in terms of .  Also convert cotangent to tangent.

Example Question #3 : Evaluating Trig Functions

Find the decimal value of 

 

Possible Answers:

Correct answer:

Explanation:

To determine the decimal value of the following trig function, , make sure that the calculator is in radian mode.

Compute the expression.

 

Example Question #4 : Evaluating Trig Functions

Determine the correct value of 

.

Possible Answers:

Correct answer:

Explanation:

The question  asks for the y-coordinate on the unit circle when the degree angle is .  

Be careful not to confuse finding the value of the angle when the y-value of the coordinate of the unit circle is .

Ensure that the calculator is in degree mode.

Example Question #5 : Evaluating Trig Functions

Find the value of 

.

Possible Answers:

Correct answer:

Explanation:

Before beginning this problem on a calculator, though this is not necessary since these are special angles, ensure that the mode of the calculator is in degrees.

Input the values of the expression and solve.

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