How do you graph #f(x) = (x^2 - 1) / (x+1)# on a coordinate graph?

1 Answer
Aug 17, 2015

You can factorise first, and then cancel.

Explanation:

#->f(x)=((x+1)(x-1))/(x+1)=(cancel((x+1))(x-1))/cancel(x+1)#

You're left with a simple linear function:
#f(x)=x-1#

BUT!!
There is a discontinuity at #x=-1#, as this would make the denominator of the original function #=0#.

But since #lim_(x->-1^-) f(x)=lim_(x->-1^+) f(x)=-2#

this discontinuity is considered removable.
graph{(x^2-1)/(x+1) [-10, 10, -5, 5]}