All Trigonometry Resources
Example Questions
Example Question #1 : Graphing Tangent And Cotangent
The following is a graph of which function?
The graph looks to have infinite range, but multiple vertical asymptotes. That means we can limit our choices to tangent and cotangent graphs.
Furthermore, we observe that the graph starts at the bottom and increases from left to right, consistent with tangent graphs. So we narrow our focus to the choices involving tangents.
To decide between the remaining two graphs, observe that y-intercept (where x=0) of our graph is (0,1).
Now evaluated at is , which means that we need a vertical shift of unit.
Hence the best choice is:
Example Question #4 : Graphing Tangent And Cotangent
Which of the following is the graph of ?
To derive the graph of , recall that . The graph of is
and the graph of is
Vertical asymptotes will occur in the graph of whenever . This is because the denominator of the tangent function will be equal to zero whenever the cosine function is equal to zero and then the entire function will be undefined at those points. Wherever cosine crosses the x-axis a vertical asymptote will occur. If we overlay the sine and cosine graphs we see the following:
So our tangent graph will follow the same form as the sine and cosine graphs when they are increasing, but will have vertical asymptotes wherever cosine crosses the x-axis.
And we are left with our graph of
Example Question #5 : Graphing Tangent And Cotangent
Which of the following is the graph of ?
We will begin by considering the general graph of and apply transformations step by step to produce a graph of . The graph of is
The general equal of a tangent transformation equation is . A is the amplitude of the graph of tangent. Here, so we do not need to apply a transformation here. Next, we will consider the period. The period of the tangent function is equal to . So the period of our graph would be
Period =
Period =
So the period is shortened from to .
Now, we will consider . is the phase shift of our graph. So we will shift our graph units to the left. This does not change our graph visually due to the period now being . Lastly, we will consider . is the vertical shift of our graph, and so we must shift our graph 1 unit up.
And we are left with the graph of .
Example Question #6 : Graphing Tangent And Cotangent
Which of the following is the graph of ?
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:
Now we will simply invert the tangent graph to get the cotangent graph
And we are left with our cotangent graph
Example Question #7 : Graphing Tangent And Cotangent
Which of the following is the graph of .
First, we will consider the graph of and apply transformations step-by-step. The graph of is
The general form of a cotangent transformation function is . For our function , and so we need to increase the amplitude 4 units.
here so we do not need to make any changes to the period of this graph. , giving us a negative phase shift of units.
This leaves us with our graph of .
Example Question #1 : Graphing Tangent And Cotangent
True or False: The period of tangent and cotangent function is .
True
False
True
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 : Graphs Of Inverse Trigonometric Functions
True or False: The inverse of the function is also a function.
True
False
False
Consider the graph of the function . It passes the vertical line test, that is if a vertical line is drawn anywhere on the graph it only passes through a single point of the function. This means that is a function.
Now, for its inverse to also be a function it must pass the horizontal line test. This means that if a horizontal line is drawn anywhere on the graph it will only pass through one point.
This is not true, and we can also see that if we graph the inverse of () that this does not pass the vertical line test and therefore is not a function. If you wish to graph the inverse of , then you must restrict the domain so that your graph will pass the vertical line test.
Example Question #1 : Graphs Of Inverse Trigonometric Functions
Which of the following is the graph of the inverse of with ?
Note that the inverse of is not , that is the reciprocal. The inverse of is also written as . The graph of with is as follows.
And so the inverse of this graph must be the following with and
Example Question #3 : Graphs Of Inverse Trigonometric Functions
Which best describes the easiest method to graph an inverse trigonometric function (or any function) based on the parent function?
The values are swapped with so where for the parent function, for the inverse function.
Let so where for the parent function for the inverse function.
The and values are switched so where for the parent function, for the inverse function.
Let so where for the parent function, for the inverse function.
Example Question #4 : Graphs Of Inverse Trigonometric Functions
Which of the following represents the graph of with ?
If we are looking for the graph of with , that means this is the inverse of with . The graph of with is
Switching the and values to graph the inverse we get the graph
Certified Tutor