Solution assignment 06 Fractional functions and graphs

Return to Assignments Fractional functions and graphs

Assignment 6

Given the function:

y=1-\displaystyle\frac{x-1}{x+1}

Find:
the vertical asymptote;
the horizontal asymptote;
the intersection point with the Y-as if it exists;
the intersection point with the X-as if it exists.

Based on these results sketch the result in the figure.

Solution

This function looks slightly different than we are used to, but after a few calculations we come on familiar ground.
We rewrite:

y=1-\displaystyle\frac{x-1}{x+1}=\displaystyle\frac{x+1}{x+1}-\displaystyle\frac{x-1}{x+1}=\displaystyle\frac{x+1-x+1}{x+1}=\displaystyle\frac{2}{x+1}

Now this function has the familiar form.
The vertical asymptote of this function is x=-1, i.e. the value for which the denominator equals 0. We find the horizontal asymptote by trying to find the value of y if x\to\infty or x\to-\infty and that is y=0, thus the X-axis. Furthermore we notice that the intersection point with the Y-axis (take x=0) is (0,2). There is no intersection point with the X-axis because the X-axis is an asymptote.
The graph is depicted in the following figure.

1-(x-1)div(x+1)

Return to Assignments Fractional functions and graphs

0
Web Design BangladeshWeb Design BangladeshMymensingh