Is This Function a Variation of a Hyperbola?

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SUMMARY

The discussion centers on the analysis of the rational function y = (x-1)² / ((x+1)(x-2)), where the user seeks to identify intercepts and asymptotes using a graphing calculator. The vertical asymptotes are established at x = -1 and x = 2, with an x-intercept at x = 1 and a y-intercept at y = -1/2. The horizontal asymptote is determined through limit calculus, yielding y = 1 as x approaches infinity. The conversation also touches on alternative methods for graphing, including polynomial division and switching variables.

PREREQUISITES
  • Understanding of rational functions and their properties
  • Familiarity with asymptotes and intercepts
  • Basic knowledge of limit calculus
  • Experience using graphing calculators for function analysis
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  • Learn how to perform polynomial long division for rational functions
  • Study the concept of horizontal asymptotes in rational functions
  • Explore graphing techniques for rational functions using graphing calculators
  • Investigate the behavior of functions as they approach infinity and negative infinity
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Students in calculus, mathematics educators, and anyone involved in graphing rational functions and analyzing their behavior.

dagg3r
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hi i got this equation
y= x^2 - 2x + 1 / X^2 -x - 2

how do i sketch this finding all intercepts, and asymptotes with a gfx calculator? Please check if the steps i did below is right

what i did i factorised the equation so i got

y= (x-1)^2 / (x+1)(x-2)

ASYMPTOTES
the bottom line (x+1)(x-2) = 0 gives me the vertical asymptotes thus
x= -1 and x=2

X-Intercept
to find the x-intercept i let y=0 thus (x-1)^2
X=1

Y-Intercept Let X=0
y=-1/2

I got those values but how do i sketch the graph it looks weird on the gfx calc is this a variation of a hyperbola? i also heard you can do stuff like use polydivion and get another equation or break it up and sketch it or something like that?
 
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dagg3r said:
I got those values but how do i sketch the graph it looks weird on the gfx calc is this a variation of a hyperbola? i also heard you can do stuff like use polydivion and get another equation or break it up and sketch it or something like that?

How precise does the graph need to be? If I were doing this for a class, I would just calculate all of the interesting points and trends and then connect the dots. For example, what happens as x goes to inf and -inf? Does y go to +inf or -inf at the critical points? I'm not sure why it won't plot on your calculator, though. Do the infinities cause problems? If so, have you tried restricting the range?
 
The horizontal asymtote needs to be calculated as well.

To do this, I am going to use limit calculus.

[tex] y = \lim_{x\rightarrow\infty} \frac{x^2 - 2x + 1}{x^2 - x - 2}[/tex]
[tex] y = \lim_{x\rightarrow\infty} \frac{\frac{x^2}{x^2} - \frac{2x}{x^2} + \frac{1}{x^2}}{\frac{x^2}{x^2} - \frac{x}{x^2} - \frac{2}{x^2}}[/tex]
[tex] y = \lim_{x\rightarrow\infty} \frac{1 - \frac{2}{x} + \frac{1}{x^2}}{1 - \frac{1}{x} - \frac{2}{x^2}}[/tex]
[tex] y = \frac{1 - 0 + 0}{1 - 0 - 0}[/tex]
y = 1

Another way to do this would be to switch x and y, solve for y, and see which values of x are undefined for that function, but the calculus method is quicker and easier IMO.
 
Last edited:

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