Better Students Ask More Questions.
How do I do the following problem: Analyze the graph of a rational function R(x)=...
1 Answer | add yours
High School Teacher
Analyze the graph of `R(x)=(8x^2+26x+15)/(2x^2-x-15)` .
(1) Factor numerator and denominator:
(2) The domain of `R(x)` is all reals except `x=-2/5,x=3` .(Cannot divide by zero)
`R(x)` is equivalent to the function `y=(4x+3)/(x-3)` except at `x=-2/5` .(Cancel the identical binomials) So the range of `R(x)` is all reals except 4. (An easy way to see this is to rewrite `(4x+3)/(x-3)` as `15/(x-3)+4` using long division, and realize that `15/(x-3)` can never be zero)
(3) The x-intercept is `x=-3/4` . The y-intercept is -1.
(4) There is a removable discontinuity at `x=-2/5` .(A "hole" in the graph). There is an infinite discontinuity at `x=3` .
(5) The graph has a horizontal asymptote at `y=4` and a vertical asymptote at `x=3` .
(6) The graph :
Posted by embizze on December 6, 2011 at 11:42 AM (Answer #1)
Join to answer this question
Join a community of thousands of dedicated teachers and students.