How to find where a function is discontinuous?

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value