Solution assignment 07 Fractional functions and graphs

Return to Assignments Fractional functions and graphs

Assignment 7

Given the function:

y=\displaystyle\frac{x^2+5x+6}{x+2}

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

The line x=-2 seems to be an asymptote. However, when we substitute this value in the formula we get \displaystyle\frac{0}{0}. That the numerator yields 0 for x=-2 means that the numerator contains the factor  x+2. Indeed, the numerator can be factorized: (x+3)(x+2). Now the function can be rewritten:

y=\displaystyle\frac{(x+3)(x+2)}{x+2}=x+3 if x\neq{-2}.

We do not need to do complicated calculations any more. There also no asymptotes. The graph of the function is equal to the graph of y=x+3, excluded the point (-2,1). The graph approaches y=1 if x approaches -2. The graph in the figure is valid, exluded the point (-2,1).

(x^2+5x+6)div(x+2)

Return to Assignments Fractional functions and graphs

0
Web Design BangladeshWeb Design BangladeshMymensingh