Bart22 --
What we need here is a good graphing function. Try this one, clicking
on the "Plot" link on the right-hand side to bring up a Java applet:
http://www.math.com/students/solvers/online_solvers.htm
Your function simplifies to:
Y = (x-3)^2/x^2
Clearly there are some key points in this graph:
X = 0
X = 3
So, we want to know what this graph looks for a range from x = -5 to
about x = 7; we'd like to see if y is ever negative (duh, it's not)
and look at a range of -1 to about 10. So set up the plot that way.
What do you see?
2. Vertical asymptote: x = 0
4. X intercept at x = 3; no Y intercept (because both L and R sides
of this discontinuous function approach infinity as x approaches 0)
5. This function is positive for all x except x = 3
---
1. Now the horizontal asymptotes: for x > 0, what limit is there for
y in this function? Trying some samples will give you a pretty good
idea:
x = 10; y = 0.49
x = 100; y = 0.9409
x = 200; y = 0.9702
So, for x > 0, the asymptote is y = 1 -- which is pretty intuitive
when you see that (any positive number minus 3) squared will always be
less than (any positive number) squared
For x < 0, you'll see that as x increases, y approaches 0 -- so y
= 0 is the asymptote on the L side
3. A little harder is the slant/oblique asymptote. A note from this
definition of an oblique asymptote on the Mathwords page:
"Oblique asymptotes always occur for rational functions which have a
numerator polynomial that is one degree higher than the denominator
polynomial."
Mathwords
"Oblique Asymptote"
http://www.mathwords.com/o/oblique_asymptote.htm
Your numerator and denominator are both second-order functions -- so
you won't have an oblique asymptote.
Google search strategy:
"graphing online"
"oblique asymptote"
Best regards,
Omnivorous-GA |