<< Chapter < Page Chapter >> Page >

The domain of csc x was given to be all x such that x k π for any integer k . Would the domain of y = A csc ( B x C ) + D be x C + k π B ?

Yes. The excluded points of the domain follow the vertical asymptotes. Their locations show the horizontal shift and compression or expansion implied by the transformation to the original function’s input.

Given a function of the form y = A csc ( B x ) , graph one period.

  1. Express the function given in the form y = A csc ( B x ) .
  2. | A | .
  3. Identify B and determine the period, P = 2 π | B | .
  4. Draw the graph of y = A sin ( B x ) .
  5. Use the reciprocal relationship between y = sin x and y = csc x to draw the graph of y = A csc ( B x ) .
  6. Sketch the asymptotes.
  7. Plot any two reference points and draw the graph through these points.

Graphing a variation of the cosecant function

Graph one period of f ( x ) = −3 csc ( 4 x ) .

  • Step 1. The given function is already written in the general form, y = A csc ( B x ) .
  • Step 2. | A | = | 3 | = 3 , so the stretching factor is 3.
  • Step 3. B = 4 , so P = 2 π 4 = π 2 . The period is π 2 units.
  • Step 4. Sketch the graph of the function g ( x ) = −3 sin ( 4 x ) .
  • Step 5. Use the reciprocal relationship of the sine and cosecant functions to draw the cosecant function .
  • Steps 6–7. Sketch three asymptotes at x = 0 , x = π 4 , and x = π 2 . We can use two reference points, the local maximum at ( π 8 , −3 ) and the local minimum at ( 3 π 8 , 3 ) . [link] shows the graph.
    A graph of one period of a cosecant function. There are vertical asymptotes at x=0, x=pi/4, and x=pi/2.
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Graph one period of f ( x ) = 0.5 csc ( 2 x ) .

A graph of one period of a modified secant function, which looks like an downward facing prarbola and a upward facing parabola.
Got questions? Get instant answers now!

Given a function of the form f ( x ) = A csc ( B x C ) + D , graph one period.

  1. Express the function given in the form y = A csc ( B x C ) + D .
  2. Identify the stretching/compressing factor, | A | .
  3. Identify B and determine the period, 2 π | B | .
  4. Identify C and determine the phase shift, C B .
  5. Draw the graph of y = A csc ( B x ) but shift it to the right by and up by D .
  6. Sketch the vertical asymptotes, which occur at x = C B + π | B | k , where k is an integer.

Graphing a vertically stretched, horizontally compressed, and vertically shifted cosecant

Sketch a graph of y = 2 csc ( π 2 x ) + 1. What are the domain and range of this function?

  • Step 1. Express the function given in the form y = 2 csc ( π 2 x ) + 1.
  • Step 2. Identify the stretching/compressing factor, | A | = 2.
  • Step 3. The period is 2 π | B | = 2 π π 2 = 2 π 1 2 π = 4.
  • Step 4. The phase shift is 0 π 2 = 0.
  • Step 5. Draw the graph of y = A csc ( B x ) but shift it up D = 1.
  • Step 6. Sketch the vertical asymptotes, which occur at x = 0 , x = 2 , x = 4.

The graph for this function is shown in [link] .

A graph of 3 periods of a modified cosecant function, with 3 vertical asymptotes, and a dotted sinusoidal function that has local maximums where the cosecant function has local minimums and local minimums where the cosecant function has local maximums.
A transformed cosecant function
Got questions? Get instant answers now!
Got questions? Get instant answers now!

Given the graph of f ( x ) = 2 cos ( π 2 x ) + 1 shown in [link] , sketch the graph of g ( x ) = 2 sec ( π 2 x ) + 1 on the same axes.

A graph of two periods of a modified cosine function. Range is [-1,3], graphed from x=-4 to x=4.
A graph of two periods of both a secant and consine function. Grpah shows that cosine function has local maximums where secant function has local minimums and vice versa.
Got questions? Get instant answers now!

Analyzing the graph of y = cot x

The last trigonometric function we need to explore is cotangent    . The cotangent is defined by the reciprocal identity cot x = 1 tan x . Notice that the function is undefined when the tangent function is 0, leading to a vertical asymptote in the graph at 0 , π , etc. Since the output of the tangent function is all real numbers, the output of the cotangent function is also all real numbers.

We can graph y = cot x by observing the graph of the tangent function because these two functions are reciprocals of one another. See [link] . Where the graph of the tangent function decreases, the graph of the cotangent function increases. Where the graph of the tangent function increases, the graph of the cotangent function decreases.

Questions & Answers

if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
Syamthanda Reply
hey , can you please explain oxidation reaction & redox ?
Boitumelo Reply
hey , can you please explain oxidation reaction and redox ?
Boitumelo
for grade 12 or grade 11?
Sibulele
the value of V1 and V2
Tumelo Reply
advantages of electrons in a circuit
Rethabile Reply
we're do you find electromagnetism past papers
Ntombifuthi
what a normal force
Tholulwazi Reply
it is the force or component of the force that the surface exert on an object incontact with it and which acts perpendicular to the surface
Sihle
what is physics?
Petrus Reply
what is the half reaction of Potassium and chlorine
Anna Reply
how to calculate coefficient of static friction
Lisa Reply
how to calculate static friction
Lisa
How to calculate a current
Tumelo
how to calculate the magnitude of horizontal component of the applied force
Mogano
How to calculate force
Monambi
a structure of a thermocouple used to measure inner temperature
Anna Reply
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4
Amahle Reply
How is energy being used in bonding?
Raymond Reply
what is acceleration
Syamthanda Reply
a rate of change in velocity of an object whith respect to time
Khuthadzo
how can we find the moment of torque of a circular object
Kidist
Acceleration is a rate of change in velocity.
Justice
t =r×f
Khuthadzo
how to calculate tension by substitution
Precious Reply
hi
Shongi
hi
Leago
use fnet method. how many obects are being calculated ?
Khuthadzo
khuthadzo hii
Hulisani
how to calculate acceleration and tension force
Lungile Reply
you use Fnet equals ma , newtoms second law formula
Masego
please help me with vectors in two dimensions
Mulaudzi Reply
how to calculate normal force
Mulaudzi
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Algebra and trigonometry. OpenStax CNX. Nov 14, 2016 Download for free at https://legacy.cnx.org/content/col11758/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Algebra and trigonometry' conversation and receive update notifications?

Ask