Trigonometry : Trigonometry

Study concepts, example questions & explanations for Trigonometry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : Arcsin, Arccos, Arctan

Soh_cah_toa

For the above triangle, what is  if  and ?

Possible Answers:

Correct answer:

Explanation:

We need to use a trigonometric function to find . We are given the opposite and adjacent sides, so we can use the  and  functions.

Example Question #2 : Arcsin, Arccos, Arctan

Soh_cah_toa

For the above triangle, what is  if  and ?

Possible Answers:

Correct answer:

Explanation:

We need to use a trigonometric function to find . We are given the opposite and hypotenuse sides, so we can use the  and  functions.

Example Question #1 : Arcsin, Arccos, Arctan

Which of the following is the degree equivalent of the inverse trigonometric function

?

Possible Answers:

Correct answer:

Explanation:

The  is the reversal of the cosine function. That means that if , then .

Therefore,

 

Example Question #3 : Arcsin, Arccos, Arctan

Assuming the angle in degrees, determine the value of .

Possible Answers:

Correct answer:

Explanation:

To evaluate , it is necessary to know the existing domain and range for these inverse functions.

Inverse sine:

Inverse cosine:

Inverse tangent:

Evaluate each term.  The final answers must return an angle.

Example Question #4 : Arcsin, Arccos, Arctan

If 

,

what value(s) does  take?

Assume that   

Possible Answers:

No real solution.

Correct answer:

Explanation:

If , then we can apply the cosine inverse to both sides:

Since cosine and cosine inverse undo each other; we can then apply sine and secant inverse functions to obtain the solution.

  and  

                                          and            

 are the two solutions. 

 

 

Example Question #3 : Arcsin, Arccos, Arctan

Calculate .

Possible Answers:

 and 

Correct answer:

Explanation:

The arcsecant function takes a trigonometric ratio on the unit circle as its input and results in an angle measure as its output. The given function can therefore be rewritten as 

 

and is the angle measure  which, when applied to the cosine function , results in . Notice that the arcsecant function as expressed in the statement of the problem is capitalized; hence, we are looking for the "principal" angle measure, or the one which lies between  and . Since , and since  lies between  and ,

.

 

Example Question #4 : Arcsin, Arccos, Arctan

Calculate .

Possible Answers:

Correct answer:

Explanation:

The domain on the argument  for  is 

 .

The range of the function  is not defined at  or , and so the domain of its inverse, , does not include those values. Hence, we must find the angle  between  and  for which .

Since , the equation  can be rewritten as 

,

or

for some x between  and .

Now,  when , since .

Therefore, 

.

Example Question #561 : Trigonometry

What is the formula for angular velocity?

Possible Answers:

Correct answer:

Explanation:

Angular velocity is a measure of the time it takes to travel over a certain arc that is formed by a central angle.   is usually used to represent the angular velocity,  is the measure of the central angle, and  is the time it takes to travel from point A to B.  This formula looks similar to the measure of an arc, , but we are considering the velocity in terms of the measure of the angle over the amount of time it took to cover that distance.



 

Example Question #1 : Angle Applications

What is the angular velocity of an angle whose measure is  when it took a point 6 seconds to rotate through the angle.

Possible Answers:

 radians/seconds

 radians/seconds

 radians/seconds

 radians/seconds

Correct answer:

 radians/seconds

Explanation:

We have enough information to plug into the angular velocity formula to solve this problem.   and  seconds.

 

 

 

So our answer is  radians/seconds

 

 

Example Question #562 : Trigonometry

True or False: The angular velocity is a measure of an angle of rotation over time.

Possible Answers:

False

True

Correct answer:

True

Explanation:

consider the figure below.  Think of line A being connected to a hinge where  is.  We are measuring the amount of time it takes for line A to rotate and align with line B.  This is a measure of angle rotation over time.



Learning Tools by Varsity Tutors