Question

lim(x approaches 3) of (x^4 -81)/(3-x) why is it a one sided limittt???

Answer 1

factor the top

Answer 2

i got the solution, it should be -108, but how is that a left sided limit?

Answer 3

it is not a one-sided limit. you get -108 from either side even though there is a hole at x=3. cubic polynomials are continuous. see also
http://www.wolframalpha.com/input/?i=lim_%28x-%3E3%29+%28x^4+-81%29%2F%283-x%29+