Consider y = f(x) = (x-2) / (x+2), does this formula define a function for -3<x< 3?

1 Answer
Mar 28, 2017

No, the rational expression is undefined when x = -2

Explanation:

When x = -2, the numerator of f(x) is color(blue)(-2)-2 = -4 while the denominator is color(blue)(-2)+2 = 0.

So the formula would say:

f(-2) = -4/0

which is undefined, since division by zero is (almost) always undefined.