I have trouble with Graphing rational functions, me,test is tomorrow

[ming2008]

I have trouble with Graphing rational functions, please help me,test is tomorrow


I do not know how to use horizontal , vertical , oblique asymptotes to graph a rathional functions.

like y=2x+3+3/x+1;
y=x^2-4/x-4


thank you very much

 

[HallsofIvy]

Well, this was posted yesterday so I imagine it is too late. (Please do not expect people to be sitting around waiting for you to post something. We do have lives.)

The first thing you need to do is write the equations properly. Surely you do not actually mean "y= 2x+ 3+ (3/x)+ 1" or "y= x^2- (4/x)-4" which is what you wrote! Use parentheses: y= 2x+ 3+ 3/(x+1)? or y= (x^2-4)/(x-4) ?

You need to look at places where the denominator of any fraction is 0. Those will be, in general, vertical asymptotes. You should also look for places where the entire function is equal to 0. Those will be places where the graph crosses the x-axis. Finally, by checking the sign of f(x) for a single x-value in each interval between such points, you can get a rough idea of what the graph looks like between.

 

[tacman]

for reaching out for help with graphing rational functions. It can definitely be a challenging topic, especially when a test is coming up. I would recommend seeking additional resources or reaching out to a tutor for extra support. In the meantime, here are a few tips that may help you with graphing rational functions:

1. Identify any vertical, horizontal, or oblique asymptotes. These are important guidelines that will help you plot the graph accurately.

2. Plot some key points on the graph by choosing different values for x and solving for y. This will help you get a sense of the overall shape of the graph.

3. Pay attention to the behavior of the function as x approaches the asymptotes. This will give you a better understanding of how the graph behaves near these points.

4. Don't forget to label your axes and include a title for your graph. This will make it easier for you to interpret and for your teacher to grade.

Remember, practice makes perfect, so don't get discouraged if you don't get it right the first time. Keep working at it and seeking help when needed. Good luck on your test tomorrow!