hi guys, i just want to know, in calculating limits, when I do direct substitution, and it gives 3/0, does it mean for sure that the limit does not exist?

Question

anonymous · Answer

not necessarily.... 
if you can simplify or reduce the function, do that first... then do direct substitution....

anonymous · Answer

o-o

anonymous · Answer

so after reduction, and it still gives 3/0, that means the answer is DNE right

anonymous · Answer

yes.... you're right.

anonymous · Answer

can you give me an example of where first direct substitution gives DNE, and after reduction the limit will exist?

anonymous · Answer

ok.... lemme think...

anonymous · Answer

$\LARGE f(x)=\frac{x^2-1}{x+1} $

$\LARGE \lim_{x \rightarrow -1} f(x) = -2 $

anonymous · Answer

ALRIGHT THANKS MATE U ARE DA BEST

anonymous · Answer

here's an example, but actually, a direct substitution will give you an INDETERMINATE form 0/0... this is different from 3/0.
you'll learn to deal with indeterminate forms later...
so i think your first answer is correct.....:)
yw....