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2.13 Limits

If there exists a real number LL such that f(x)f(x) gets close to LL whenever xx tends to bb, then we call LL the limit and write

f(x)Lasxb, orL=limxbf(x).f(x)\rightarrow L\quad{\hbox{as}}\quad x\rightarrow b,\quad{\hbox{or}}\quad L=% \lim_{x\rightarrow b}f(x).

The full definition of this is given in MATH 113. Note that xx does not equal bb, although xx is close to bb; further, f(x)f(x) may never be equal to LL. In this notation, bb and LL are fixed; whereas xx and f(x)f(x) vary. It is not good to confuse the notation by writing limxbf(x)L.\lim_{x\rightarrow b}f(x)\rightarrow L.