Question

calculate the following limits

Answer 1

You just substitute x=3 into the equations.

Answer 2

1) You do NOT substitute to find a limit. A limit APPROACHES.
2) The problem, as presented, makes no sense. What limits?

Answer 3

The problem is to find the limits of f(x) as x approaches 3 from both left and right, which is why substitution will do.

Answer 4

You must FIRST demonstrate continuity before substitution is acceptable.