Inverse trigonometric functions

Click For Summary

Homework Help Overview

The discussion revolves around creating an equation for a reciprocal trigonometric function, specifically focusing on its domain and range. The original poster seeks to formulate an equation that adheres to the specified domain of \(x \neq \frac{5\pi}{6} + \frac{\pi}{3}n\) and a range of \(y \leq 1\) or \(y \geq 9\).

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss potential forms for the function, such as \(y = 4 \sec(\cdot) + 5\) or \(y = 4 \csc(\cdot) + 5\), and explore the implications of the range on these forms. There are inquiries about the nature of the function at prohibited points and the reasoning behind the function being even. Some participants also examine the mapping of \(x\) values to \(\theta\) values in the context of the function's periodicity.

Discussion Status

The conversation is ongoing, with participants providing insights into the behavior of the function at specific points and discussing the relationship between the domain and the function's undefined values. There is a collaborative exploration of how to approach the problem, but no consensus has been reached on a definitive solution.

Contextual Notes

Participants are working under the constraints of the homework assignment, which specifies the domain and range requirements. There is a focus on understanding the implications of these constraints on the function's behavior.

MartynaJ
Messages
18
Reaction score
1
Homework Statement
Create one equation of a reciprocal trigonometric function that has the following:
Domain: ##x\neq \frac{5\pi}{6}+\frac{\pi}{3}n##
Range: ##y\le1## or ##y\ge9##
Relevant Equations
See above please...
Create one equation of a reciprocal trigonometric function that has the following:
Domain: ##x\neq \frac{5\pi}{6}+\frac{\pi}{3}n##
Range: ##y\le1## or ##y\ge9##

I think the solution has to be in the form of ##y=4sec( )+5## OR ##y=4csc( )+5##, but I am not sure on what to include in the brackets.
I got the ##4## and the ##5## from the range, since ##5-4=1## and ##5+4=9##. Here I put ##5## as the equation of axis and ##4## as the amplitude.
 
Physics news on Phys.org
I assume at the prohibited x points with ##\pi/3## distance the function diverge to ##\pm \infty##.
The function is an even function. ##f(2n\pi/3),f((2n+1)\pi/3)##=1 or 9.
 
Last edited:
anuttarasammyak said:
I assume at the prohibited x points with ##\pi/3## distance the function diverge to ##\pm \infty##.
The function is an even function. f(0)=1 or 9.
why ##\frac{\pi}{3}## and not ##\frac{5\pi}{6}+\frac{\pi}{3}##?
 
I took n is any integer and the prohibited points are
x=... ,-5\pi/6,-\pi/2,-\pi/6,\pi/6,\pi/2,5\pi/6,...
 
anuttarasammyak said:
I took n is any integer and the prohibited points are
x=...,−5π/6,−π/2,−π/6,π/6,π/2,5π/6,...
Ya sorry I now understand how you got these values... But how did you know it is an even function?
 
Values of ##5\pi/6+n\pi/3## for n=..., -4,-3,-2,-1,0,...

##cosec\ 0=\pm \infty## but f(0) is a definite value.

Now your assumption comes to
\frac{y-5}{4}=\pm \sec mx
Find appropriate m to adjust period.
 
Last edited:
MartynaJ said:
Homework Statement:: Create one equation of a reciprocal trigonometric function that has the following:
Domain: ##x\neq \frac{5\pi}{6}+\frac{\pi}{3}n##
Range: ##y\le1## or ##y\ge9##
Relevant Equations:: See above please...

Create one equation of a reciprocal trigonometric function that has the following:
Domain: ##x\neq \frac{5\pi}{6}+\frac{\pi}{3}n##
Range: ##y\le1## or ##y\ge9##

I think the solution has to be in the form of ##y=4sec( )+5## OR ##y=4csc( )+5##, but I am not sure on what to include in the brackets.
I got the ##4## and the ##5## from the range, since ##5-4=1## and ##5+4=9##. Here I put ##5## as the equation of axis and ##4## as the amplitude.
Consider ##y = 4 \sec \theta + 5##. It's undefined at the points ##\theta = m\pi + \frac \pi 2##. The function ##f(x)## you want is undefined at points ##x = n \frac \pi 3 + \frac{5 \pi}6##. What you want to do is find how to map the values of ##x## to the values of ##\theta##. Let's take ##m=n## for simplicity. Then you want to find a function ##\theta(x)## that takes ##x = 5\pi/6## to ##\theta = \pi/2##, ##x = 5\pi/6 + \pi/3## to ##\theta=\pi/2 + \pi##, and so on. Every time ##x## increases by ##\pi/3##, you want ##\theta## to increase by ##\pi##.

If you can't see where this is headed, try plotting a few pairs of ##(x,\theta)##.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K