How do you graph the rational function #f(x)=6/(x^2+x-2)#?
1 Answer
I would factorize the denominator solving the second degree equation to get:
This helps you to "see" the forbidden points, i.e., the points where the denominator becomes zero (you do not want this!!!).
They are:
Excluding these two values of
You can now try to figure out the shape of your graph:
1) for x very big positively or negatively your function gets very small or, better, tends to zero (try to substitute in your function, say,
2) getting near to -2 your function gets very big positively (from the left) and negatively (from the right). You can try it by substituting
3) setting
At the end your graph looks like:
graph{6/(x^2+x-2) [-10, 10, -5, 5]}
hope it helps