Trigonometry : Trigonometry

Study concepts, example questions & explanations for Trigonometry

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Example Questions

Example Question #6 : Graphing Tangent And Cotangent

Which of the following is the graph of ?

Possible Answers:

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Correct answer:

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Explanation:

To derive the graph of  recall that .  So the tangent and cotangent graphs are reciprocals of one another.  We will consider the tangent graph since it is one we are more familiar with:

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Now we will simply invert the tangent graph to get the cotangent graph

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And we are left with our cotangent graph

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Example Question #7 : Graphing Tangent And Cotangent

Which of the following is the graph of .

Possible Answers:

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Correct answer:

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Explanation:

First, we will consider the graph of  and apply transformations step-by-step.  The graph of  is

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The general form of a cotangent transformation function is .  For our function ,  and so we need to increase the amplitude 4 units.

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 here so we do not need to make any changes to the period of this graph.  , giving us a negative phase shift of  units.

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This leaves us with our graph of .

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Example Question #1 : Graphing Tangent And Cotangent

True or False: The period of tangent and cotangent function is .

Possible Answers:

True

False

Correct answer:

True

Explanation:

This is because  and   causing the tangent function to be undefined at these points and forming a vertical asymptote.  This is also true for the cotangent function because  so wherever  is zero or undefined, cotangent will be as well.

Example Question #1 : Understanding Trigonometric Equations

A triangle has sides , ,  of lengths , ,  respectively. The angle opposite each side is called , , , respectively. The sine of which angle and the cosine and which different angle will both yield 

In the answer, list the sine first and the cosine second.

Possible Answers:

Correct answer:

Explanation:

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This is the figure being described in the problem, and as sine is opposite over hypotenuse and cosine adjacent over hypotenuse, the sine of  and the cosine of  will yield the correct answer.

Example Question #2 : Understanding Trigonometric Equations

Solve the equation over the domain  (answer in degrees).

Possible Answers:

Correct answer:

Explanation:

Rearrange algebraically so that,

 .

Over the interval 0 to 360 degrees, sinx = 1 when x equals 90 degrees.

Example Question #2 : Trigonometric Equations

Solve each equation over the domain  (answer in degrees). 

Possible Answers:

Correct answer:

Explanation:

First, think of the angle values for which . (This is the equivalent of taking the arctan.)

.

The angles for which this is true are 45 degrees and 225 degrees.

We set x-15 equal to those two angles and solve for x, giving us 60 and 240. 

Example Question #161 : Trigonometry

Solve each equation over the domain  (answer in degrees).

Possible Answers:

Correct answer:

Explanation:

Rearrange the equation so that,

 .

Recall the angles over the interval 0 to 360 degrees for which sec is equal to 2.

These are 60 and 300 degrees.

Set x+7 equal to these angle measures and then find that x equals 53 and 293. 

Example Question #1 : Setting Up Trigonometric Equations

Solve each equation over the interval  

Possible Answers:

Correct answer:

Explanation:

Rearrange the equation so that,

 .

Take the square of both sides and then recall the angle measures for which,

.

These measures over the interval 

 .

Example Question #2 : Setting Up Trigonometric Equations

Solve each quation over the interval 

Possible Answers:

Correct answer:

Explanation:

Rearrange the equation so that,

.

Take the square of both sides and find the angles for which

.

These two angles are  and .

Example Question #2 : Trigonometric Equations

Solve for  using trigonometric ratios. 

Set up trig 1

Possible Answers:

Correct answer:

Explanation:

To solve for x, first set up a trigonometric equation using the information provided in the diagram. The two side lengths given are the hypotenuse, x, and the side opposite the given angle, 6. We can set up our equation like this:

The sine of is , so we can substitue that in:

cross multiplying gives us .

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