The Range of a Function in Set Y

AI Thread Summary
The discussion revolves around the concept of the range of a function in relation to the set of all possible output values, Set Y. It highlights that a function's range does not have to encompass every element in Set Y, using the example of the function f(x) = x/(x+1), which approaches but never reaches y=1. The participant confirms that while y=1 is part of Set Y, it is not included in the function's range due to the vertical asymptote at x=-1. Additionally, it is clarified that x=-1 is not in the domain of the function, as the domain consists of all possible input values. The conversation concludes with a festive note, wishing participants a Merry Christmas and Happy New Year.
kripkrip420
Messages
54
Reaction score
0

Homework Statement


N/A


Homework Equations


N/A


The Attempt at a Solution



I guess I will start here. My question does not necessarily involve equations. In the Calculus book I am currently studying from, I am reviewing some pre-calculus and I came across a section that mentioned the range of the function does not have to be the entire Set Y. Now, what I was wondering was what exactly this means. Here are my thoughts.

Let's say you have a function f(x)=(x)/(x+1)

This function has a vertical asymptote at x=(-1)

This function also approaches a y-value y=1.

I am assuming that when the Calculus book said that the range doesn't always include every element in a Set Y, this is something like what they were referring to. Even thought the function doesn't ever get to y=1, that doesn't mean that y=1 is not included in the Set Y, correct? y=1 is still present in the Set Y even though the functions range does not include it. Am I correct in saying this? Also, x=(-1) is NOT in the domain of x correct? This is because the domain is defined as the Set D of all POSSIBLE input values. The Set Y is all the real numbers that extend through the real line y, whereas, the range is simply the output values of the function that may or may not include all the elements of the Set Y. Am I correct in what I have said so far?

Thank you very much in advance to everyone who has taken their time to answer my simple question!
 
Physics news on Phys.org
Yes, this is entirely correct!
 
Wow. Thank you for the lightning fast response! Also, I forgot to mention... Merry Christmas to you if you celebrate it and Merry Christmas to everyone else that celebrates it as well! Happy New Year!
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Essentially I just have this problem that I'm stuck on, on a sheet about complex numbers: Show that, for ##|r|<1,## $$1+r\cos(x)+r^2\cos(2x)+r^3\cos(3x)...=\frac{1-r\cos(x)}{1-2r\cos(x)+r^2}$$ My first thought was to express it as a geometric series, where the real part of the sum of the series would be the series you see above: $$1+re^{ix}+r^2e^{2ix}+r^3e^{3ix}...$$ The sum of this series is just: $$\frac{(re^{ix})^n-1}{re^{ix} - 1}$$ I'm having some trouble trying to figure out what to...
Back
Top